Iroha is very particular about numbers. There are K digits that she dislikes: D_1, D_2, ..., D_K.

She is shopping, and now paying at the cashier. Her total is N yen (the currency of Japan), thus she has to hand at least N yen to the cashier (and possibly receive the change).

However, as mentioned before, she is very particular about numbers. When she hands money to the cashier, the decimal notation of the amount must not contain any digits that she dislikes. Under this condition, she will hand the minimum amount of money.

Find the amount of money that she will hand to the cashier.

Constraints

* 1 ≦ N < 10000
* 1 ≦ K < 10
* 0 ≦ D_1 < D_2 < … < D_K≦9
* \\{D_1,D_2,...,D_K\\} ≠ \\{1,2,3,4,5,6,7,8,9\\}

Input

The input is given from Standard Input in the following format:


N K
D_1 D_2 … D_K


Output

Print the amount of money that Iroha will hand to the cashier.

Examples

Input

1000 8
1 3 4 5 6 7 8 9


Output

2000


Input

9999 1
0


Output

9999
import java.util.*;
import java.util.function.*;
import java.util.stream.*;
import java.util.Map.Entry;
// import static java.util.Arrays.compare;
import static java.util.Arrays.fill;
import static java.util.Arrays.sort;
import static java.util.Collections.sort;
import static java.util.Comparator.reverseOrder;
// import static java.util.List.of;
import static java.util.Objects.isNull;
import static java.util.Objects.nonNull;
import static java.util.Objects.hash;

import java.io.*;

import java.math.BigInteger;
import static java.math.BigInteger.ZERO;
import static java.math.BigInteger.ONE;
// import static java.math.BigInteger.TWO;
import static java.math.BigInteger.TEN;

import static java.lang.Math.PI;
import static java.lang.Math.E;
import static java.lang.Math.min;
import static java.lang.Math.max;
import static java.lang.Math.abs;
import static java.lang.Math.sin;
import static java.lang.Math.cos;
import static java.lang.Math.tan;
import static java.lang.Math.asin;
import static java.lang.Math.acos;
import static java.lang.Math.atan;
import static java.lang.Math.atan2;
import static java.lang.Math.hypot;
import static java.lang.Math.sqrt;
import static java.lang.Math.log;
import static java.lang.Math.exp;
import static java.lang.String.format;
import static java.lang.System.exit;
import static java.lang.System.currentTimeMillis;

public class Main{
   public static void main(String[] args){
      FastScanner fsc = new FastScanner();
      int n=fsc.nextInt();
      int k=fsc.nextInt();
      boolean[] d=new boolean[10];
      for(int i=0;i<k;i++) d[fsc.nextInt()]=true;
      for(int i=n;;i++){
         char[] c=Integer.toString(i).toCharArray();
         boolean b=true;
         for(char ch:c){
            if(d[ch-'0']) b=false;
         }
         if(b){
            System.out.println(i);
            return;
         }
      }
   }
}


class ArrayUtil{
    public static int[] input(FastScanner fsc, int n){
        int[] a=new int[n];
        for(int i=0;i<n;i++){
            a[i]=fsc.nextInt();
        }
        return a;
    }
    public static int[][] input(FastScanner fsc, int n, int m){
        int[][] a=new int[n][m];
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                a[i][j]=fsc.nextInt();
            }
        }
        return a;
    }
    public static int[] map(IntUnaryOperator op, int[] a){
        int[] b=new int[a.length];
        for(int i=0;i<a.length;i++) b[i] = op.applyAsInt(a[i]);
        return b;
    }
    /**
     * s[i] is the sum of the range [0, i) in a.
     * @param a
     * @return cumulative sum array of a.
     */
    public static int[] cumsum(int[] a){
        int n=a.length;
        int[] s=new int[n+1];
        for(int i=1;i<=n;i++){
            s[i]=s[i-1]+a[i-1];
        }
        return s;
    }
    public static int[][] cumsum(int[][] a){
        int n=a.length;
        int m=a[0].length;
        int[][] s=new int[n+1][m+1];
        for(int i=1;i<=n;i++){
            for(int j=1;j<=m;j++){
                s[i][j]=s[i-1][j]+s[i][j-1]-s[i-1][j-1]+a[i-1][j-1];
            }
        }
        return s;
    }
    public static void reverse(int[] a, int begin, int end){
        for(int i=begin;i<begin+(end-begin)/2;i++){
            swap(a, i, begin+end-i-1);
        }
    }
    public static void reverse(int[] a){
        reverse(a, 0, a.length);
    }
    public static void revSort(int[] a){
        Arrays.sort(a);
        reverse(a);
    }
    public static int[] nextPermutation(int[] a){
        int[] ret=a.clone();
        int n=ret.length;
        for(int i=n-1;i>=1;i--){
            if(ret[i]>ret[i-1]){
                int fail=n, pass=i;
                while(fail-pass>1){
                    int mid=pass+(fail-pass)/2;
                    if(ret[mid]>ret[i-1]) pass=mid;
                    else fail=mid;
                }
                swap(ret, pass, i-1);
                reverse(ret, i, n);
                return ret;
            }
        }
        return null;
    }
    public static int[] predPermutation(int[] a){
        int[] ret=a.clone();
        int n=ret.length;
        for(int i=n-1;i>=1;i--){
            if(ret[i]<ret[i-1]){
                int fail=n, pass=i;
                while(fail-pass>1){
                    int mid=pass+(fail-pass)/2;
                    if(ret[mid]<ret[i-1]) pass=mid;
                    else fail=mid;
                }
                swap(ret, pass, i-1);
                reverse(ret, i, n);
                return ret;
            }
        }
        return null;
    }
    public static void swap(int[] a, int u, int v){
        int tmp=a[u];
        a[u]=a[v];
        a[v]=tmp;
    }
    public static int compare(int[] a, int[] b){
        for(int i=0;i<a.length;i++){
            if(i>=b.length){
                return -1;
            } else if(a[i]>b[i]){
                return 1;
            } else if(a[i]<b[i]){
                return -1;
            }
        }
        if(a.length<b.length){
            return 1;
        } else{
            return 0;
        }
    }
    public static boolean equals(int[] a, int[] b){
        return compare(a, b)==0;
    }

    /*
     *      IntArray
     * _________________________
     *      LongArray
     */

    public static long[] linput(FastScanner fsc, int n){
        long[] a=new long[n];
        for(int i=0;i<n;i++){
            a[i]=fsc.nextLong();
        }
        return a;
    }
    public static long[][] linput(FastScanner fsc, int n, int m){
        long[][] a=new long[n][m];
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                a[i][j]=fsc.nextLong();
            }
        }
        return a;
    }
    public static long[] map(LongUnaryOperator op, long[] a){
        long[] b=new long[a.length];
        for(int i=0;i<a.length;i++) b[i]=op.applyAsLong(a[i]);
        return b;
    }
    /**
     * s[i] is the sum of the range [0, i) in a.
     * @param a
     * @return cumulative sum array of a.
     */
    public static long[] cumsum(long[] a){
        int n=a.length;
        long[] s=new long[n+1];
        for(int i=1;i<=n;i++){
            s[i]=s[i-1]+a[i-1];
        }
        return s;
    }
    public static long[][] cumsum(long[][] a){
        int n=a.length;
        int m=a[0].length;
        long[][] s=new long[n+1][m+1];
        for(int i=1;i<=n;i++){
            for(int j=1;j<=m;j++){
                s[i][j]=s[i-1][j]+s[i][j-1]-s[i-1][j-1]+a[i-1][j-1];
            }
        }
        return s;
    }
    public static void reverse(long[] a, int begin, int end){
        for(int i=begin;i<begin+(end-begin)/2;i++){
            long tmp=a[i];
            a[i]=a[begin+end-i-1];
            a[begin+end-i-1]=tmp;
        }
    }
    public static void reverse(long[] a){
        reverse(a, 0, a.length);
    }
    public static void revSort(long[] a){
        Arrays.sort(a);
        reverse(a);
    }
    public static void compress(long[] a){
        int n=a.length;
        long[] sorted = a.clone();
        Arrays.sort(sorted);
        for(int i=0;i<n;i++){
            int l=0, r=n;
            while(r-l>1){
                int m=l+(r-l)/2;
                if(sorted[m]<=a[i]) l=m;
                else r=m;
            }
            a[i]=l;
        }
    }
    public static long[] nextPermutation(long[] a){
        long[] ret=a.clone();
        int n=ret.length;
        for(int i=n-1;i>=1;i--){
            if(ret[i]>ret[i-1]){
                int fail=n, pass=i;
                while(fail-pass>1){
                    int mid=pass+(fail-pass)/2;
                    if(ret[mid]>ret[i-1]) pass=mid;
                    else fail=mid;
                }
                swap(ret, pass, i-1);
                reverse(ret, i, n);
                return ret;
            }
        }
        return null;
    }
    public static long[] predPermutation(long[] a){
        long[] ret=a.clone();
        int n=ret.length;
        for(int i=n-1;i>=1;i--){
            if(ret[i]<ret[i-1]){
                int fail=n, pass=i;
                while(fail-pass>1){
                    int mid=pass+(fail-pass)/2;
                    if(ret[mid]<ret[i-1]) pass=mid;
                    else fail=mid;
                }
                swap(ret, pass, i-1);
                reverse(ret, i, n);
                return ret;
            }
        }
        return null;
    }
    public static void swap(long[] a, int u, int v){
        long tmp=a[u];
        a[u]=a[v];
        a[v]=tmp;
    }
    public static int compare(long[] a, long[] b){
        for(int i=0;i<a.length;i++){
            if(i>=b.length){
                return -1;
            } else if(a[i]>b[i]){
                return 1;
            } else if(a[i]<b[i]){
                return -1;
            }
        }
        if(a.length<b.length){
            return 1;
        } else{
            return 0;
        }
    }
    public static boolean equals(long[] a, long[] b){
        return compare(a, b)==0;
    }
}


class BellmanFord{
    public long[] bellmanFord(Node[] nodes, int s){
        int n = nodes.length;
        boolean negativeLoop[] = new boolean[n];
        long[] d = new long[n];
        fill(d, Const.LINF);
        d[s] = 0;
        for(int i = 0; i < n; i++){
            for(int from = 0; from < n; from++){
                for(Edge edge: nodes[from].edges){
                    int to = edge.to;
                    long c = edge.cost;
                    if(d[to] > d[from] + c){
                        d[to] = d[from]+c;
                    }
                }
            }
        }           
        for(int i = 0; i < n; i++){
            for(int from = 0; from < n; from++){
                for(Edge edge: nodes[from].edges){
                    int to = edge.to;
                    long c = edge.cost;
                    if(d[to] > d[from] + c){
                        negativeLoop[to] = true;
                        d[to] = -Const.LINF;
                    }
                    if(negativeLoop[from]){
                        negativeLoop[to] = true;
                        d[to] = -Const.LINF;
                    }
                }
            }
        }
        return d;
    }
    public long bellmanFord(Node[] nodes, int s, int t){
        return bellmanFord(nodes, s)[t];
    }
}

/**
 * BinaryIndexedTree(n=10): [ 8 ] [ 4 ] [ 2 ] [ 6 ] [ 10 ] [1] [3] [5] [7] [9]
 * 
 * original array: (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
 * 
 * if you want to get the sum of range (l, r], caluculate S(r)-S(l). (S(n) means
 * \sum_{i=1}^n array[i].)
 * 
 * then, you need to be able to calculate S(n) quickly. actually, you can.
 * 
 * 1. binarize n. Ex: n=5(10)=101(2). 2. decompose
 * n=2**p_1+2**p_2+...+2**p_m.(p_1<...<p_m) Ex: n=1+100. 3. acutually,
 * S(n)=\sum_{i=1}^m{tree[\sum_{j=i}^m 2**p_j]} Ex: S(n)=tree[101]+tree[100].
 * 
 * computational complexity of sum-query is O(log n).
 */

class BinaryIndexedTree{
    private int[] tree;
    private int[] originalArray;
    private int n;
    /**
     * @param array 0-indexed array.
     */
    public BinaryIndexedTree(int[] array){
        this.originalArray = array.clone();
        this.n = array.length;
        this.tree = new int[n+1];
        init();
    }
    public BinaryIndexedTree(int initial, int n){
        this.originalArray = new int[n];
        this.n = n;
        this.tree = new int[n+1];
        for(int i = 0; i < n; i++) originalArray[i] = initial;
        init();
    }
    public BinaryIndexedTree(int n){
        this(0, n);
    }
    private void init(){
        for(int i = 1; i <= n; i++){
            tree[i] += originalArray[i-1];
            int parent = i + (-i & i);
            if(parent <= n) tree[parent] += tree[i];
        }
    }

    /**
     * Calculate the sum of range (l, r] in array (1-indexed).
     * @param l left border (open)
     * @param r right border (closed)
     * @return sum of range (l, r] in array (1-indexed).
     */
    public int sum(int l, int r){
        return sum(r) - sum(l);
    }
    public int sum(int r){
        int ret = 0;
        for(; r > 0; r -= -r & r) ret += tree[r];
        return ret;
    }
    public int sum(){
        return sum(n);
    }

    /**
     * add v to array[i] and update BIT.
     * @param i index of array (1-indexed)
     * @param v adding value
     */
    public void add(int i, int v){
        originalArray[i-1] += v;
        for(; i <= n; i += -i & i) tree[i] += v;
    }

    /**
     * update the value of array[i] to v and update BIT.
     * @param i index of array (1-indexed)
     * @param v adding value
     */
    public void update(int i, int v){
        add(i, v - originalArray[i-1]);
        originalArray[i] = v;
    }

    @Override
    public String toString(){
        int msb=0;
        for(int m=n;m>>1!=0;m>>=1, msb++);
        char[][] c=new char[msb+1][1<<(2*msb+1)];
        int[] indx=new int[msb+1];
        for(int i=1;i<=n;i++){
            int j=0;
            for(int l=-i&i;l>>1!=0;l>>=1, j++);
            char[] intc=Integer.toString(tree[i]).toCharArray();
            int intl=intc.length;
            c[j][indx[j]]='[';
            c[j][indx[j]+(1<<(j+2))-1]=']';
            int st=indx[j]+(1<<(j+1))-intl/2-1;
            for(int l=0;l<intl;l++){
                c[j][st+l]=intc[l];
            }
            indx[j]+=1<<(j+3);
        }
        StringBuilder sb=new StringBuilder();
        for(int i=msb;i>=0;sb.append(String.valueOf(c[i--])).append("\n"));
        return sb.toString();
    }
}


class Complex implements Cloneable{
    public static final double PI=Math.PI;
    public static final Complex I=new Complex(0, 1);
    public static final Complex ZERO=new Complex(0, 0);
    public static final Complex ONE=new Complex(1, 0);

    public double x;
    public double y;
    public double r;
    public double theta;

    public Complex(double x, double y){
        this.x=x;
        this.y=y;
        this.r=Math.hypot(x, y);
        this.theta=Math.atan2(y, x);
    }
    public Complex(double r, double theta, boolean radian){
        this.r=r;
        if(radian){
            this.theta=theta;
        } else{
            this.theta=Math.toRadians(theta);
        }
        this.x=this.r*Math.cos(this.theta);
        this.y=this.r*Math.sin(this.theta);
    }
    public Complex(double theta, boolean radian){
        this(1., theta, radian);
    }

    private double re(){
        return x;
    }
    private double im(){
        return y;
    }
    private double abs(){
        return r;
    }
    private double arg(){
        return theta;
    }
    private Complex conj(){
        return new Complex(x, -y);
    }
    private double sin(){
        return Math.sin(arg());
    }
    private double cos(){
        return Math.cos(arg());
    }
    private double tan(){
        return Math.tan(arg());
    }
    private Complex rot(double phi, boolean radian){
        return new Complex(r, theta+(radian?phi:Math.toRadians(phi)), true);
    }
    private Complex exp(int n){
        return new Complex(Math.pow(r, n), theta*n, true);
    }
    private double dist(Complex c){
        return abs(this.sub(c));
    }

    private Complex add(Complex c){
        return new Complex(x+c.x, y+c.y);
    }
    private Complex sub(Complex c){
        return new Complex(x-c.x, y-c.y);
    }
    private Complex mul(Complex c){
        return new Complex(x*c.x-y*c.y, x*c.y+y*c.x);
    }
    private Complex div(Complex c){
        double retx, rety;
        if(c.equals(ZERO)){
            if(x>0){
                retx=Double.POSITIVE_INFINITY;
            } else if(x<0){
                retx=Double.NEGATIVE_INFINITY;
            } else{
                retx=Double.NaN;
            }
            if(y>0){
                rety=Double.POSITIVE_INFINITY;
            } else if(y<0){
                rety=Double.NEGATIVE_INFINITY;
            } else{
                rety=Double.NaN;
            }
            return new Complex(retx, rety);
        }
        return mul(div(this, c.r), new Complex(-c.theta, true));
    }

    private Complex add(double r){
        return new Complex(x+r, y);
    }
    private Complex sub(double r){
        return new Complex(x-r, y);
    }
    private Complex mul(double r){
        return new Complex(x*r, y*r);
    }
    private Complex div(double r){
        return new Complex(x/r, y/r);
    }

    public static Complex conj(Complex c){
        return c.conj();
    }
    public static double re(Complex c){
        return c.re();
    }
    public static double im(Complex c){
        return c.im();
    }
    public static double abs(Complex c){
        return c.abs();
    }
    public static double arg(Complex c){
        return c.arg();
    }
    public static double sin(Complex c){
        return c.sin();
    }
    public static double cos(Complex c){
        return c.cos();
    }
    public static double tan(Complex c){
        return c.tan();
    }
    public static Complex rot(Complex c, double phi, boolean radian){
        return c.rot(phi, radian);
    }
    public static Complex exp(Complex c, int n){
        return c.exp(n);
    }
    public static double dist(Complex a, Complex b){
        return a.dist(b);
    }
    public static Complex[] nthRoot(int n){
        Complex[] ret=new Complex[n];
        for(int i=0;i<n;i++){
            ret[i]=new Complex(2.*PI*i/n, true);
        }
        return ret;
    }

    public static Complex add(Complex a, Complex... c){
        Complex ret=a.clone();
        for(Complex b:c){
            ret=ret.add(b);
        }
        return ret;
    }
    public static Complex sub(Complex a, Complex... c){
        Complex ret=a.clone();
        for(Complex b:c){
            ret=ret.sub(b);
        }
        return ret;
    }
    public static Complex mul(Complex a, Complex... c){
        Complex ret=a.clone();
        for(Complex b:c){
            ret=ret.mul(b);
        }
        return ret;
    }
    public static Complex div(Complex a, Complex... c){
        Complex ret=a.clone();
        for(Complex b:c){
            ret=ret.div(b);
        }
        return ret;
    }

    public static Complex add(Complex a, double r, Complex... c){
        return add(a.add(r), c);
    }
    public static Complex sub(Complex a, double r, Complex... c){
        return sub(a.sub(r), c);
    }
    public static Complex mul(Complex a, double r, Complex... c){
        return mul(a.mul(r), c);
    }
    public static Complex div(Complex a, double r, Complex... c){
        return div(a.div(r), c);
    }

    public static Complex pM(Complex a, Complex b){
        return div(add(a, b), 2.);
    }
    public static Complex internalDivision(Complex a, Complex b, int m, int n){
        return div(add(mul(a, n), mul(b, m)), m+n);
    }
    public static Complex externalDivision(Complex a, Complex b, int m, int n){
        return internalDivision(a, b, -m, n);
    }

    public static Complex pG(Complex a, Complex b, Complex c){
        return div(add(a, b, c), 3.); 
    }
    public static Complex pH(Complex a, Complex b, Complex c){
        double tanA=Math.tan(arg(c, a, b));
        double tanB=Math.tan(arg(a, b, c));
        double tanC=Math.tan(arg(b, c, a));
        return div(add(mul(a, tanA), mul(b, tanB), mul(c, tanC)), tanA + tanB + tanC);
    }
    public static Complex pI(Complex a, Complex b, Complex c){
        double la=abs(sub(b, c));
        double lb=abs(sub(c, a));
        double lc=abs(sub(a, b));
        return div(add(mul(a, la), mul(b, lb), mul(c, lc)), la + lb + lc);
    }
    public static Complex pO(Complex a, Complex b, Complex c){
        double la=abs(sub(b, c)); la*=la;
        double lb=abs(sub(c, a)); lb*=lb;
        double lc=abs(sub(a, b)); lc*=lc;
        double sa=la*(lb+lc-la);
        double sb=lb*(lc+la-lb);
        double sc=lc*(la+lb-lc);
        return div(add(mul(a, sa), mul(b, sb), mul(c, sc)), sa+sb+sc);
    }
    public static Complex[] pIabc(Complex a, Complex b, Complex c){
        Complex[] pIabc=new Complex[3];
        pIabc[0]=pI(mul(a, -1.), b, c);
        pIabc[1]=pI(a, mul(b, -1.), c);
        pIabc[2]=pI(a, b, mul(c, -1.));
        return pIabc;
    }

    public static boolean onLine(Complex a, Complex b, Complex... c){
        for(Complex z:c){
            if(PI-arg(a, b, z)>=0.0000001){
                return false;
            }
        }
        return true;
    }

    public static double arg(Complex a, Complex b, Complex c){
        double arg=arg(div(sub(c, b), sub(a, b)));
        if(arg<0){
            arg*=-1.;
        }
        return arg;
    }

    private Complex(double x, double y, double r, double theta){
        this.x=x;
        this.y=y;
        this.r=r;
        this.theta=theta;
    }

    @Override 
    public Complex clone(){
        return new Complex(this.x, this.y, this.r, this.theta);
    }
    @Override
    public boolean equals(Object o){
        if(o==this){
            return true;
        } else if(o instanceof Complex){
            Complex c=(Complex) o;
            if(c.x==this.x && c.y==this.y && c.r==this.r && c.theta==this.theta){
                return true;
            } else{
                return false;
            }
        } else{
            return false;
        }
    }
    @Override
    public int hashCode(){
        return Objects.hash(x, y, r, theta);
    }
    @Override
    public String toString(){
        return "(x, y) = ("+x+", "+y+"), (r, theta) = ("+r+", "+theta+").";
    }
}

class Const{
    public static long MOD = 1_000_000_007;
    public static final long LINF = 1_000_000_000_000_000_000l;
    public static final int IINF = 1_000_000_000;
    public static void setMod(long mod){
        MOD = mod;
    }
}


class Coordinate{
    private static double PI=Math.PI;
    private static double DELTA=0.0000001;
    private static double P_INF=1e100;
    private static double N_INF=-1e100;
    private static double NaN=Double.NaN;

    public static double innerProduct(Complex u, Complex v){
        return u.x*v.x+u.y+v.y;
    }
    public static double outerProductZ(Complex u, Complex v){
        return u.x*v.y-u.y*v.x;
    }

    public static Complex pM(Complex a, Complex b){
        return Complex.div(Complex.add(a, b), 2.);
    }
    public static Complex internalDivision(Complex a, Complex b, int m, int n){
        return Complex.div(Complex.add(Complex.mul(a, n), Complex.mul(b, m)), m+n);
    }
    public static Complex externalDivision(Complex a, Complex b, int m, int n){
        return internalDivision(a, b, -m, n);
    }

    public static Complex pG(Complex a, Complex b, Complex c){
        if(!isTriangle(a, b, c)){
            return null;
        }
        return Complex.div(Complex.add(a, b, c), 3.); 
    }
    public static Complex pH(Complex a, Complex b, Complex c){
        if(!isTriangle(a, b, c)){
            return null;
        }
        Complex pO=pO(a, b, c);
        return Complex.add(Complex.sub(a, pO), Complex.sub(b, pO), Complex.sub(c, pO), pO);
    }
    public static Complex pI(Complex a, Complex b, Complex c){
        if(!isTriangle(a, b, c)){
            return null;
        }
        double la=Complex.dist(b, c);
        double lb=Complex.dist(c, a);
        double lc=Complex.dist(a, b);
        return Complex.div(Complex.add(Complex.mul(a, la), Complex.mul(b, lb), Complex.mul(c, lc)), la + lb + lc);
    }
    public static Complex pO(Complex a, Complex b, Complex c){
        if(!isTriangle(a, b, c)){
            return null;
        }
        double la=Complex.distSq(b, c);
        double lb=Complex.distSq(c, a);
        double lc=Complex.distSq(a, b);
        double sa=la*(lb+lc-la);
        double sb=lb*(lc+la-lb);
        double sc=lc*(la+lb-lc);
        return Complex.div(Complex.add(Complex.mul(a, sa), Complex.mul(b, sb), Complex.mul(c, sc)), sa+sb+sc);
    }
    public static Complex[] pIabc(Complex a, Complex b, Complex c){
        if(!isTriangle(a, b, c)){
            return null;
        }
        Complex[] pIabc=new Complex[3];
        pIabc[0]=pI(Complex.mul(a, -1.), b, c);
        pIabc[1]=pI(a, Complex.mul(b, -1.), c);
        pIabc[2]=pI(a, b, Complex.mul(c, -1.));
        return pIabc;
    }

    public static boolean onLine(Line l, Complex c){
        return Math.abs(l.a*c.x+l.b*c.y+l.c)<DELTA && c.x>=l.lx && c.x<=l.rx && c.y>=l.ly && c.y<=l.ry;
    }

    public static boolean oneLine(Complex a, Complex b, Complex c){
        if(a.equals(b) || b.equals(c) || c.equals(a)){
            return true;
        }
        double arg=arg(a, b, c);
        return arg<=DELTA || arg>=PI-DELTA;
    }

    public static boolean isTriangle(Complex a, Complex b, Complex c){
        return !oneLine(a, b, c);
    }

    public static double dist(Line l, Complex c){
        return Math.abs(l.a*c.x+l.b*c.y+l.c);
    }

    public static Complex crossPoint(Line l1, Line l2){
        Complex o=l1.begin;
        Complex v1=Complex.sub(l1.end, o);
        Complex v2=Complex.sub(l2.begin, o);
        Complex v3=Complex.sub(l2.end, o);
        double opz12=Coordinate.outerProductZ(v1, v2);
        double opz13=Coordinate.outerProductZ(v1, v3);
        if((opz12>0 && opz13>0) || (opz12<0 && opz13<0)){
            return null;
        }
        double p=l1.a*l2.b-l2.a*l1.b;
        double qx=l1.b*l2.c-l2.b*l1.c;
        double qy=l2.a*l1.c-l1.a*l2.c;
        if(Math.abs(p)<=DELTA){
            if(Math.abs(qx)<=DELTA && Math.abs(qy) <= DELTA){
                return new Complex(NaN, NaN);
            } else{
                return new Complex(P_INF, P_INF);
            }
        } else{
            return new Complex(qx/p, qy/p);
        }
    }

    public static Complex[] crossPoint(Circle c, Line l){
        double d=dist(l, c.c);
        if(c.r<d){
            return null;
        } else if(c.r-d<DELTA){
            Complex v=Complex.mul(new Complex(l.a, l.b), c.r);
            Complex p=onLine(l, Complex.add(c.c, v))?Complex.add(c.c, v):Complex.sub(c.c, v);
            Complex[] ret={p};
            return ret;
        } else{
            if(c.in(l.begin) && c.in(l.end)){
                return null;
            } else {
                ArrayList<Complex> cross=new ArrayList<>();
                Complex v=Complex.mul(new Complex(l.a, l.b), d);
                for(int i=0;i<2;i++){
                    Complex h=i==0?Complex.add(c.c, v):Complex.sub(c.c, v);
                    for(int j=0;j<2;j++){
                        Complex mov=j==0?new Complex(-l.b, l.a):new Complex(l.b, -l.a);
                        Complex p=Complex.add(h, mov);
                        if(onLine(l, p)){
                            cross.add(p);
                        }
                    }
                }
                return (Complex[]) cross.toArray();
            }
        }
    }

    public static Complex[] crossPoint(Circle c1, Circle c2){
        double d=Complex.dist(c1.c, c2.c);
        if(d>c1.r+c2.r+DELTA){
            return null;
        } else if(Math.abs(c1.r+c2.r-d)<=DELTA){
            Complex[] ret={Complex.mul(Complex.sub(c2.c, c1.c), c1.r/d)};
            return ret;
        } else if(d>Math.abs(c1.r-c2.r)+DELTA){
            double a=c1.r, b=c2.r;
            double l=(a+b+d)*(a+b-d)*(a-b+d)*(-a+b+d)/(4*d*d);
            Complex h=Complex.mul(Complex.sub(c2.c, c1.c), (d*d+a*a-b*b)/(2*d*d));
            Line line=Line.create(c1.c, c2.c, false, false);
            Complex mov=Complex.mul(new Complex(line.b, -line.a), l);
            Complex[] ret={Complex.add(h, mov), Complex.sub(h, mov)};
            return ret;
        } else if(Math.abs(Math.abs(c1.r-c2.r)-d)<=DELTA){
            if(c1.r>c2.r){
                Complex[] ret={Complex.mul(Complex.sub(c2.c, c1.c), c1.r/d)};
                return ret;
            } else if(c1.r<c2.r){
                Complex[] ret={Complex.mul(Complex.sub(c1.c, c2.c), c2.r/d)};
                return ret;
            } else{
                Complex[] ret={new Complex(NaN, NaN)};
                return ret;
            }
        } else{
            return null;
        }
    }

    public static double arg(Complex a, Complex b, Complex c){
        double arg=Complex.arg(Complex.div(Complex.sub(c, b), Complex.sub(a, b)));
        if(arg<0){
            arg*=-1.;
        }
        return arg;
    }

    static class Circle{
        public Complex c;
        public double r;
         
        public Circle(Complex center, double radius){
            this.c=center;
            this.r=Math.abs(radius);
        }

        public boolean inon(Complex z){
            return Complex.dist(c, z) <= r + DELTA;
        }
        public boolean in(Complex z){
            return Complex.dist(c, z) < r-DELTA;
        }
        public boolean on(Complex z){
            return inon(z) && !in(z);
        }
    }

    static class Line{
        // a*a+b*b=1.
        public double a, b ,c;
        public double t;
        public double lx, rx, ly, ry;
        public Complex begin, end;

        public static Line create(Complex a, Complex b, boolean extendA, boolean extendB){
            if(a.x>b.x){
                return new Line(b, a, extendB, extendA);
            } else {
                return new Line(a, b, extendA, extendB);
            }
        }

        private Line(Complex a, Complex b, boolean extendA, boolean extendB){
            this.a=b.y-a.y;
            this.b=a.x-b.x;
            this.c=-a.x*b.y+b.x*a.y;
            double hp=Math.hypot(this.a, this.b);
            this.a/=hp;
            this.b/=hp;
            this.c/=hp;
            if(a.x==b.x){
                this.t=P_INF;
                if(a.y<b.y){
                    if(!extendA){
                        this.begin=a.clone();
                        this.lx=a.x;
                        this.ly=a.y;
                    } else{
                        this.begin=new Complex(this.lx=a.x, this.ly=N_INF);
                    }
                    if(!extendB){
                        this.end=b.clone();
                        this.rx=b.x;
                        this.ry=b.y;
                    } else{
                        this.end=new Complex(this.rx=b.x, this.ry=P_INF);
                    }
                }
            } else {
                this.t=(b.y-a.y)/(b.x-a.x);
                if(!extendA){
                    this.begin=a.clone();
                    this.lx=a.x;
                    this.ly=a.y;
                } else{
                    if(t>0){
                        if(t>=1.){
                            this.begin=new Complex(this.lx=x(N_INF), this.ly=N_INF);
                        } else{
                            this.begin=new Complex(this.lx=N_INF, this.ly=y(N_INF));
                        }
                    } else{
                        if(t<=-1.){
                            this.begin=new Complex(this.lx=x(P_INF), this.ly=P_INF);
                        } else{
                            this.begin=new Complex(this.lx=N_INF, this.ly=y(N_INF));
                        }
                    }
                }
                if(!extendB){
                    this.end=b.clone();
                    this.rx=b.x;
                    this.ry=b.y;
                } else{
                    if(t>0){
                        if(t>=1.){
                            this.begin=new Complex(this.rx=x(P_INF), this.ry=P_INF);
                        } else{
                            this.begin=new Complex(this.rx=P_INF, this.ry=y(P_INF));
                        }
                    } else{
                        if(t<=-1.){
                            this.begin=new Complex(this.rx=x(N_INF), this.ry=N_INF);
                        } else{
                            this.begin=new Complex(this.rx=P_INF, this.ry=y(P_INF));
                        }
                    }
                }
            }
        }
        
        private double x(double y){
            return -(b*y+c)/a;
        }
        private double y(double x){
            return -(a*x+c)/b;
        }
    }

    static class Complex implements Cloneable{
        public static final Complex I=new Complex(0, 1);
        public static final Complex ZERO=new Complex(0, 0);
        public static final Complex ONE=new Complex(1, 0);
    
        public double x;
        public double y;
        public double r;
        public double theta;
    
        public Complex(double x, double y){
            this.x=x;
            this.y=y;
            this.r=Math.hypot(x, y);
            this.theta=Math.atan2(y, x);
        }
        public Complex(double r, double theta, boolean radian){
            this.r=r;
            if(!radian){
                theta=Math.toRadians(theta);
            }
            this.theta=theta%PI;
            this.x=this.r*Math.cos(this.theta);
            this.y=this.r*Math.sin(this.theta);
        }
        public Complex(double theta, boolean radian){
            this(1., theta, radian);
        }
    
        private double re(){
            return x;
        }
        private double im(){
            return y;
        }
        private double abs(){
            return r;
        }
        private double arg(){
            return theta;
        }
        private Complex conj(){
            return new Complex(x, -y);
        }
        private double sin(){
            return Math.sin(arg());
        }
        private double cos(){
            return Math.cos(arg());
        }
        private double tan(){
            return Math.tan(arg());
        }
        private Complex rot(double phi, boolean radian){
            return new Complex(r, theta+(radian?phi:Math.toRadians(phi)), true);
        }
        private Complex exp(int n){
            return new Complex(Math.pow(r, n), theta*n, true);
        }
        private double dist(Complex c){
            return abs(this.sub(c));
        }
        private double distSq(Complex c){
            return c.x*c.x+c.y*c.y;
        }
    
        private Complex add(Complex c){
            return new Complex(x+c.x, y+c.y);
        }
        private Complex sub(Complex c){
            return new Complex(x-c.x, y-c.y);
        }
        private Complex mul(Complex c){
            return new Complex(x*c.x-y*c.y, x*c.y+y*c.x);
        }
        private Complex div(Complex c){
            double retx, rety;
            if(c.equals(ZERO)){
                if(x>0){
                    retx=Double.POSITIVE_INFINITY;
                } else if(x<0){
                    retx=Double.NEGATIVE_INFINITY;
                } else{
                    retx=NaN;
                }
                if(y>0){
                    rety=Double.POSITIVE_INFINITY;
                } else if(y<0){
                    rety=Double.NEGATIVE_INFINITY;
                } else{
                    rety=NaN;
                }
                return new Complex(retx, rety);
            }
            return mul(div(this, c.r), new Complex(-c.theta, true));
        }
    
        private Complex add(double r){
            return new Complex(x+r, y);
        }
        private Complex sub(double r){
            return new Complex(x-r, y);
        }
        private Complex mul(double r){
            return new Complex(x*r, y*r);
        }
        private Complex div(double r){
            return new Complex(x/r, y/r);
        }
    
        public static Complex conj(Complex c){
            return c.conj();
        }
        public static double re(Complex c){
            return c.re();
        }
        public static double im(Complex c){
            return c.im();
        }
        public static double abs(Complex c){
            return c.abs();
        }
        public static double arg(Complex c){
            return c.arg();
        }
        public static double sin(Complex c){
            return c.sin();
        }
        public static double cos(Complex c){
            return c.cos();
        }
        public static double tan(Complex c){
            return c.tan();
        }
        public static Complex rot(Complex c, double phi, boolean radian){
            return c.rot(phi, radian);
        }
        public static Complex exp(Complex c, int n){
            return c.exp(n);
        }
        public static double dist(Complex a, Complex b){
            return a.dist(b);
        }
        public static double distSq(Complex a, Complex b){
            return a.distSq(b);
        }
        public static Complex[] nthRoot(int n){
            Complex[] ret=new Complex[n];
            for(int i=0;i<n;i++){
                ret[i]=new Complex(2.*PI*i/n, true);
            }
            return ret;
        }
    
        public static Complex add(Complex a, Complex... c){
            Complex ret=a.clone();
            for(Complex b:c){
                ret=ret.add(b);
            }
            return ret;
        }
        public static Complex sub(Complex a, Complex... c){
            Complex ret=a.clone();
            for(Complex b:c){
                ret=ret.sub(b);
            }
            return ret;
        }
        public static Complex mul(Complex a, Complex... c){
            Complex ret=a.clone();
            for(Complex b:c){
                ret=ret.mul(b);
            }
            return ret;
        }
        public static Complex div(Complex a, Complex... c){
            Complex ret=a.clone();
            for(Complex b:c){
                ret=ret.div(b);
            }
            return ret;
        }
    
        public static Complex add(Complex a, double r, Complex... c){
            return add(a.add(r), c);
        }
        public static Complex sub(Complex a, double r, Complex... c){
            return sub(a.sub(r), c);
        }
        public static Complex mul(Complex a, double r, Complex... c){
            return mul(a.mul(r), c);
        }
        public static Complex div(Complex a, double r, Complex... c){
            return div(a.div(r), c);
        }
    
        private Complex(double x, double y, double r, double theta){
            this.x=x;
            this.y=y;
            this.r=r;
            this.theta=theta;
        }
    
        @Override 
        public Complex clone(){
            return new Complex(this.x, this.y, this.r, this.theta);
        }
        @Override
        public boolean equals(Object o){
            if(o==this){
                return true;
            } else if(o instanceof Complex){
                Complex c=(Complex) o;
                // if(c.x==this.x && c.y==this.y && c.r==this.r && c.theta==this.theta){
                //     return true;
                // } else{
                //     return false;
                // }
                return dist(c)<DELTA;
            } else{
                return false;
            }
        }
        @Override
        public int hashCode(){
            return Objects.hash(x, y, r, theta);
        }
        @Override
        public String toString(){
            return 
            "(x, y) = ("+x+", "+y+"), (r, theta(rad), theta(deg)) = ("+r+", "+theta+", "+Math.toDegrees(theta)+").";
        }
    }
}


class Dijkstra{
    public static Info dijkstra(Node[] nodes, int s){
        return dijkstra(nodes, s, -1);
    }   
    public static Info dijkstra(Node[] nodes, int s, int t){
        int n = nodes.length;
        int[] prev = new int[n];
        long[] d = new long[n];
        Queue<Integer> pq = new PriorityQueue<>((u, v) -> Long.compare(d[u], d[v]));
        fill(d, Const.LINF);
        d[s] = 0;
        pq.add(s);
        while(pq.size() > 0){
            int now = pq.poll();
            if(now == t) break;
            for(Edge e: nodes[now].edges){
                int next = e.to;
                long c = e.cost;
                if(d[now] + c < d[next]){
                    d[next] = d[now] + c;
                    prev[next] = now;
                    pq.add(next);
                }
            }
        }
        return new Info(prev, d);
    }

    public static int[] path(Info info, int from, int to){
        ArrayList<Integer> rev=new ArrayList<>();
        for(int now = to; now != from; now = info.prev[now]){
            rev.add(now);
        }
        rev.add(from);
        int[] path = new int[rev.size()];
        for(int i = 0; i < path.length; i++) path[i] = rev.get(path.length - i - 1);
        return path;
    }

    static class Info{
        public int[] prev;
        public long[] d;
        public Info(int[] prev, long[] d){
            this.prev=prev;
            this.d=d;
        }
        public int prev(int i){
            return prev[i];
        }
        public long d(int to){
            return d[to];
        }
    }
}


//caluculate maximum-flow in O(|E|*|V|^2), but often fast.
class Dinic{
    static void addEdge(int from, int to, long cap, Node[] nodes) {
        nodes[from].edges.add(new Edge(to, cap, nodes[to].edges.size()));
        nodes[to].edges.add(new Edge(from, 0l, nodes[from].edges.size() - 1));
    }

    static long dinic(int s, int t, int n, Node[] nodes) {
        long flow = 0;
        int[] level, iter;
        while (true) {
            level = bfs(s, t, n, nodes);
            if (level[t] < 0) {
                break;
            }
            iter = new int[n];
            long f = dfs(s, t, nodes, Const.LINF, level, iter);
            while (f > 0) {
                flow += f;
                f = dfs(s, t, nodes, Const.LINF, level, iter);
            }
        }
        return flow;
    }

    private static int[] bfs(int s, int t, int n, Node[] nodes) {
        IntQueue iq = new IntQueue(n);
        iq.addLast(s);
        int[] level = new int[n];
        fill(level, -1);
        level[s] = 0;
        while (iq.size() > 0) {
            int now = iq.pollFirst();
            for (Edge e : nodes[now].edges) {
                if (level[e.to] < 0 && e.cap > 0) {
                    iq.addLast(e.to);
                    level[e.to] = level[now] + 1;
                }
            }
        }
        return level;
    }

    private static long dfs(int now, int t, Node[] nodes, long f, int[] level, int[] iter) {
        if (now == t) return f;
        for (int i = iter[now]++; i < nodes[now].edges.size(); i++) {
            Edge e = nodes[now].edges.get(i);
            if (level[now] < level[e.to] && e.cap > 0) {
                long d = dfs(e.to, t, nodes, Math.min(f, e.cap), level, iter);
                if (d > 0) {
                    e.cap -= d;
                    nodes[e.to].edges.get(e.rev).cap += d;
                    return d;
                }
            }
        }
        return 0;
    }
}


class DuplicateSet<T>{
    private HashMap<T, Integer> map=new HashMap<>();
    @SafeVarargs
    public DuplicateSet(T... elements){
        for(T e:elements){
            if(!map.containsKey(e)){
                map.put(e, 0);
            }
            map.put(e, map.get(e)+1);
        }
    }
    public DuplicateSet(Collection<T> elements){
        for(T e:elements){
            if(!map.containsKey(e)){
                map.put(e, 0);
            }
            map.put(e, map.get(e)+1);
        }
    }

    @Override
    public String toString(){
        String str="";
        for(Entry<T, Integer> e:map.entrySet()){
            str+="("+e.getKey().toString()+"=> "+e.getValue()+") ";
        }
        return str;
    }

    @SuppressWarnings("unchecked")
    @Override
    public boolean equals(Object obj) {
        if(obj==this){
            return true;
        } else if(obj.getClass().equals(this.getClass())){
            DuplicateSet<T> ds=(DuplicateSet<T>) obj;
            return this.map.equals(ds.map);
        } else{
            return false;
        }
    }
    @Override
    public int hashCode(){
        return map.hashCode();
    }
}

class Edge{
    public int from;
    public int to;
    public long cost;
    public long cap;
    public int rev;
    public Edge(int to, long cap, int rev) {
        this.to = to;
        this.cap = cap;
        this.rev = rev;
    }
    public Edge(int from, int to, long cost){
        this.from = from;
        this.to = to;
        this.cost=cost;
    }
    public Edge(int from, int to){
        this.from = from;
        this.to = to;
    }
    public Edge(int to, long cost){
        this.to = to;
        this.cost = cost;
    }
}


class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}

// caluculate maximum-flow in O(|E|*F). F is the maximum-flow.
class FordFulkerson{
    static void addEdge(int fr, int to, long cap, Node[] nodes) {
        nodes[fr].edges.add(new Edge(to, cap, nodes[to].edges.size()));
        nodes[to].edges.add(new Edge(fr, 0l, nodes[fr].edges.size() - 1));
    }

    static long fordFulkerson(int s, int t, int n, Node[] nodes) {
        long flow = 0;
        boolean[] used;
        while (true) {
            used = new boolean[n];
            long f = dfs(s, t, nodes, Const.LINF, used);
            flow += f;
            if(f <= 0) break;
        }
        return flow;
    }

    private static long dfs(int now, int t, Node[] nodes, long f, boolean[] used) {
        if(now == t) return f;
        used[now] = true;
        for (int i = 0; i < nodes[now].edges.size(); i++) {
            Edge e = nodes[now].edges.get(i);
            if (!used[e.to] && e.cap > 0) {
                long d = dfs(e.to, t, nodes, Math.min(f, e.cap), used);
                if (d > 0) {
                    e.cap -= d;
                    nodes[e.to].edges.get(e.rev).cap += d;
                    return d;
                }
            }
        }
        return 0;
    }
}



class Graph{
    public Node[] nodes;
    public Edge[] edges;
    public int n;
    public int m;

    private int mIndx = 0;

    public Graph(int n, int m){
        this.nodes = new Node[n];
        for(int i = 0; i < n; i++) nodes[i] = new Node(i);
        this.edges = new Edge[m];
        this.n = n;
        this.m = m;
    }

    public void addDirectedEdge(int from, int to, long cost){
        Edge e = new Edge(from, to, cost);
        nodes[from].edges.add(e);
        nodes[to].in++;
        edges[mIndx++] = e;
    }
    public void addNonDirectedEdge(int from, int to, long cost){
        Edge e = new Edge(from, to, cost);
        Edge er = new Edge(to, from, cost);
        nodes[from].edges.add(e);
        nodes[to].edges.add(er);
        nodes[from].in++;
        nodes[to].in++;
        edges[mIndx++] = e;
    }
    public void addDirectedEdge(int from, int to){
        addDirectedEdge(from, to, 1l);
    }
    public void addNonDirectedEdge(int from, int to){
        addNonDirectedEdge(from, to, 1l);
    }
    public void addCapEdge(int from, int to, long cap) {
        nodes[from].edges.add(new Edge(to, cap, nodes[to].edges.size()));
        nodes[to].edges.add(new Edge(from, 0l, nodes[from].edges.size() - 1));
    }
    public void setNodeWeight(long[] w){
        for(int i = 0; i < n; i++) nodes[i].w = w[i];
    }

    public long[] bellmanFord(int s){
        int n = nodes.length;
        boolean negativeLoop[] = new boolean[n];
        long[] d = new long[n];
        fill(d, Const.LINF);
        d[s] = 0;
        for(int i = 0; i < n; i++){
            for(int from = 0; from < n; from++){
                for(Edge edge: nodes[from].edges){
                    int to = edge.to;
                    long c = edge.cost;
                    if(d[to] > d[from] + c){
                        d[to] = d[from]+c;
                    }
                }
            }
        }           
        for(int i = 0; i < n; i++){
            for(int from = 0; from < n; from++){
                for(Edge edge: nodes[from].edges){
                    int to = edge.to;
                    long c = edge.cost;
                    if(d[to] > d[from] + c){
                        negativeLoop[to] = true;
                        d[to] = -Const.LINF;
                    }
                    if(negativeLoop[from]){
                        negativeLoop[to] = true;
                        d[to] = -Const.LINF;
                    }
                }
            }
        }
        return d;
    }
    public long bellmanFord(int s, int t){
        return bellmanFord(s)[t];
    }

    public Info dijkstra(int s){
        return dijkstra(s, -1);
    }   
    public Info dijkstra(int s, int t){
        int[] prev = new int[n];
        long[] d = new long[n];
        Queue<Integer> pq = new PriorityQueue<>((u, v) -> Long.compare(d[u], d[v]));
        fill(d, Const.LINF);
        d[s] = 0;
        pq.add(s);
        while(pq.size() > 0){
            int now = pq.poll();
            if(now == t) break;
            for(Edge e: nodes[now].edges){
                int next = e.to;
                long c = e.cost;
                if(d[now] + c < d[next]){
                    d[next] = d[now] + c;
                    prev[next] = now;
                    pq.add(next);
                }
            }
        }
        return new Info(prev, d);
    }

    public int[] dijkstraPath(Info info, int from, int to){
        ArrayList<Integer> rev=new ArrayList<>();
        for(int now = to; now != from; now = info.prev[now]){
            rev.add(now);
        }
        rev.add(from);
        int[] path = new int[rev.size()];
        for(int i = 0; i < path.length; i++) path[i] = rev.get(path.length - i - 1);
        return path;
    }

    static class Info{
        public int[] prev;
        public long[] d;
        public Info(int[] prev, long[] d){
            this.prev=prev;
            this.d=d;
        }
        public int prev(int i){
            return prev[i];
        }
        public long d(int to){
            return d[to];
        }
    }

    public long dinic(int s, int t) {
        long flow = 0;
        int[] level, iter;
        while (true) {
            level = dinicBFS(s, t);
            if (level[t] < 0) {
                break;
            }
            iter = new int[n];
            long f = dinicDFS(s, t, Const.LINF, level, iter);
            while (f > 0) {
                flow += f;
                f = dinicDFS(s, t, Const.LINF, level, iter);
            }
        }
        return flow;
    }

    private int[] dinicBFS(int s, int t) {
        IntQueue iq = new IntQueue(n);
        iq.addLast(s);
        int[] level = new int[n];
        fill(level, -1);
        level[s] = 0;
        while (iq.size() > 0) {
            int now = iq.pollFirst();
            for (Edge e : nodes[now].edges) {
                if (level[e.to] < 0 && e.cap > 0) {
                    iq.addLast(e.to);
                    level[e.to] = level[now] + 1;
                }
            }
        }
        return level;
    }

    private long dinicDFS(int now, int t, long f, int[] level, int[] iter) {
        if (now == t) return f;
        for (int i = iter[now]++; i < nodes[now].edges.size(); i++) {
            Edge e = nodes[now].edges.get(i);
            if (level[now] < level[e.to] && e.cap > 0) {
                long d = dinicDFS(e.to, t, Math.min(f, e.cap), level, iter);
                if (d > 0) {
                    e.cap -= d;
                    nodes[e.to].edges.get(e.rev).cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

    public long fordFulkerson(int s, int t){
        long flow = 0;
        boolean[] used;
        while (true) {
            used = new boolean[n];
            long f = fordFulkersonDFS(s, t, Const.LINF, used);
            flow += f;
            if(f <= 0) break;
        }
        return flow;
    }

    private long fordFulkersonDFS(int now, int t, long f, boolean[] used) {
        if(now == t) return f;
        used[now] = true;
        for (int i = 0; i < nodes[now].edges.size(); i++) {
            Edge e = nodes[now].edges.get(i);
            if (!used[e.to] && e.cap > 0) {
                long d = fordFulkersonDFS(e.to, t, Math.min(f, e.cap), used);
                if (d > 0) {
                    e.cap -= d;
                    nodes[e.to].edges.get(e.rev).cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

    public Edge[] kruskal(){
        UnionFindTree t = new UnionFindTree(n);
        PriorityQueue<Edge> pq = new PriorityQueue<>((u, v) -> Long.compare(u.cost, v.cost));
        for(Edge e:edges) pq.add(e);
        Edge[] ret=new Edge[n-1];
        int index = 0;
        while(pq.size() > 0 && index < n){
            Edge e = pq.poll();
            if(!t.isSame(e.from, e.to)){
                t.unite(e.from, e.to);
                ret[index++] = e;
            }
        }
        return ret;
    }

    public Edge[] prim(){
        HashSet<Integer> connected = new HashSet<>();
        connected.add(0);
        PriorityQueue<Edge> pq = new PriorityQueue<>((u, v) -> Long.compare(u.cost, v.cost));
        for(Edge e: nodes[0].edges) pq.add(e);
        Edge[] ret = new Edge[n-1];
        int index = 0; 
        while(pq.size() > 0 && connected.size() < n){
            Edge e = pq.poll();
            for(int i = 0; i < 2; i++){
                int v = i==0 ? e.from : e.to;
                if(!connected.contains(v)){
                    ret[index++] = e;
                    connected.add(v);
                    for(Edge edge: nodes[v].edges){
                        if(!connected.contains(edge.from) || !connected.contains(edge.to)) pq.add(edge);
                    }
                    break;
                }
            }
        }
        return ret;
    }

    public int[] topologicalSort(){
        int[] ret = new int[n];
        IntQueue zeros=new IntQueue(3 * n);
        for(Node node: nodes) if(node.in == 0) zeros.addLast(node.id);
        int index = 0;
        while(zeros.size() > 0){
            int v = zeros.pollFirst();
            for(Edge e: nodes[v].edges) if(--nodes[e.to].in == 0) zeros.addLast(e.to);
            ret[index++]=v;
        }
        if(index < n) return null;
        return ret;
    }

    // for example (n=9)
    // [1, 8] -> [2, 5, 6] -> [3, 7] -> [4] -> [9]
    // => length:5
    public int topologicalShortestPathLength(){
        int ret = 0;
        IntQueue zeros = new IntQueue(3 * n);
        for(Node node: nodes) if(node.in == 0) zeros.addLast(node.id);
        int num = zeros.size();
        while(zeros.size() > 0){
            int size = zeros.size();
            while(size > 0){
                int v = zeros.pollFirst();
                size--;
                for(Edge e: nodes[v].edges){
                    int u = e.to;
                    if(--nodes[u].in == 0){
                        zeros.addLast(u);
                        num++;
                    }
                }
            }
            ret++;
        }
        if(num < n) return -1;
        return ret;
    }

    public long[] bfs(int s) {
        IntQueue q = new IntQueue(n);
        q.addLast(s);
        long[] d = new long[n];
        fill(d, -1);
        d[s] = 0;
        while(q.size() > 0){
            int now = q.pollFirst();
            for(Edge e: nodes[now].edges){
                int next = e.to;
                if(d[next] < 0){
                    d[next] = d[now] + e.cost;
                    q.addLast(next);
                }
            }
        }
        return d;
    }

    // return the shortest path from 's' to 't' as an array.
    // [s, a1, a2, ..., ak, t] => distance = array.length-1
    // if NO path from 's' to 't' exists, returns NULL.
    public int[] bfsPath(int s, int t){
        IntQueue q = new IntQueue(n);
        q.addLast(s);
        int[] d = new int[n];
        int[] prev = new int[n];
        prev[t] = -1;
        fill(d, -1);
        d[s] = 0;
        while(q.size() > 0){
            int now = q.pollFirst();
            for(Edge e: nodes[now].edges){
                int next = e.to;
                if(d[next] < 0){
                    d[next] = d[now] + 1;
                    prev[next] = prev[s];
                    q.addLast(next);
                }
            }
        }
        if(prev[t] < 0) return null;
        int now = t;
        int[] path = new int[d[t] + 1];
        for (int i = 0; i <= d[t]; i++) {
            path[d[t] - i] = now;
            now = prev[now];
        }
        return path;
    }

    public int[] _01bfs(int s){
        ArrayDeque<Integer> dq = new ArrayDeque<>();
        dq.add(s);
        int[] d = new int[n];
        boolean[] visited=new boolean[n];
        fill(d, Const.IINF);
        d[s] = 0;
        while (dq.size() > 0) {
            int now = dq.pollFirst();
            if(visited[now]) continue;
            visited[now] = true;
            for (Edge e: nodes[now].edges) {
                int next = e.to;
                int cost = (int) e.cost;
                if (d[next] > d[now]) {
                    if (cost == 0) {
                        dq.addFirst(next);
                    } else {
                        dq.addLast(next);
                    }
                    d[next] = d[now] + cost;
                }
            }
        }
        return d;
    }
}

class IntQueue {
    private int[] a;
    private int head = 0, tail = 0;

    public IntQueue(int max) {
        a=new int[max+2];
    }

    public void addLast(int x) {
        a[tail++]=x;
    }

    public int pollFirst() {
        if(tail==head) {
            try {
                throw new Exception("no elements.");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return a[head++];
    }

    public int pollLast() {
        if(tail==head) {
            try {
                throw new Exception("no elements.");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return a[tail--];
    }

    public int getFirst() {
        return a[head];
    }

    public int getLast() {
        return a[tail-1];
    }

    public int size() {
        return tail-head;
    }

    public void init() {
        head=0;
        tail=0;
    }
}


class IntUtil {
    public static int min(int... a) {
        int ret = Const.IINF;
        for (int c : a) {
            ret = Math.min(ret, c);
        }
        return ret;
    }

    public static int max(int... a) {
        int ret = -Const.IINF;
        for (int c : a) {
            ret = Math.max(ret, c);
        }
        return ret;
    }

    /**
     * Caluculate the ceil of a/b. Returns the smallest integer greater than or
     * equal to a/b while 'a/b' rounds fractional parts to ZERO.
     * 
     * @param a
     * @param b
     * @return the smallest integer greater than or equal to a/b
     */
    public static int cld(int a, int b) {
        if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
            if (b > 0) {
                return (a + b - 1) / b;
            } else {
                return (a + b + 1) / b;
            }
        } else {
            return a / b;
        }
    }

    /**
     * Caluculate the floor of a/b. Returns the largest integer less than or equal
     * to a/b while 'a/b' rounds fractional parts to ZERO.
     * 
     * @param a
     * @param b
     * @return the largest integer less than or equal to a/b
     */
    public static int fld(int a, int b) {
        if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
            return a / b;
        } else {
            if (b > 0) {
                return (a - b + 1) / b;
            } else {
                return (a - b - 1) / b;
            }
        }
    }

    public static int fold(IntBinaryOperator func, int a, int... b) {
        int ret = a;
        for (int c : b) {
            ret = func.applyAsInt(ret, c);
        }
        return ret;
    }
}


// minimum spanning tree
class Kruskal{
    public static Edge[] kruskal(int n, Edge[] edges){
        UnionFindTree t = new UnionFindTree(n);
        PriorityQueue<Edge> pq = new PriorityQueue<>((u, v) -> Long.compare(u.cost, v.cost));
        for(Edge e:edges) pq.add(e);
        Edge[] ret=new Edge[n-1];
        int index = 0;
        while(pq.size() > 0 && index < n){
            Edge e=pq.poll();
            if(!t.isSame(e.from, e.to)){
                t.unite(e.from, e.to);
                ret[index++]=e;
            }
        }
        return ret;
    }
}


class LazySegmentTree{
    private long[] tree;
    private long[] lazy;
    private long idElm;
    private long defaultLazyValue;
    private LongBinaryOperator operator;
    private LongBinaryOperator updateFunction;
    private LongBinaryOperator mergeLazyFunction;
    private BiFunction<Long, Integer, Long> collapseUpdateFunction;
    private int size;
    private int leafs;
    private int height;
    private int baseOfLeaf;

    public LazySegmentTree(long[] t, LongBinaryOperator operator, long idElm, LongBinaryOperator updateFunction, LongBinaryOperator mergeLazyFunction , BiFunction<Long, Integer, Long> collapseUpdateFunction, long defaultLazyValue){
        int n = t.length;
        this.operator = operator;
        this.idElm = idElm;
        this.updateFunction = updateFunction;
        this.mergeLazyFunction = mergeLazyFunction;
        this.collapseUpdateFunction = collapseUpdateFunction;
        this.defaultLazyValue = defaultLazyValue;
        this.height = minimumPowerOfTwo(n);
        this.leafs = 1 << this.height;
        this.baseOfLeaf = this.leafs - 1;
        this.size = 2 * this.leafs - 1;
        this.lazy = new long[this.size];
        this.tree = new long[this.size];
        for(int i = size - 1; i >= 0; i--) {
            if(i >= baseOfLeaf + n) {
                this.tree[i] = this.idElm;
            } else if(isLeaf(i)) {
                this.tree[i] = t[i - baseOfLeaf];
            } else{
                this.tree[i] = operator.applyAsLong(this.tree[left(i)], this.tree[right(i)]);
            }
        }
    }

    public void applyForSegment(int l, int r, long v){
        applyForSegment(new Range(l, r), 0, new Range(0, leafs), v);
    }
    private long applyForSegment(Range queryRange, int k, Range treeRange, long v){
        evaluate(k, treeRange);
        if(queryRange.crosses(treeRange)) {
            if(queryRange.contains(treeRange)) {
                lazy[k] = mergeLazyFunction.applyAsLong(lazy[k], v);
                return updateFunction.applyAsLong(tree[k], collapseUpdateFunction.apply(lazy[k], treeRange.length()));
            } else {
                long left = applyForSegment(queryRange, left(k), treeRange.leftHalf(), v);
                long right = applyForSegment(queryRange, right(k), treeRange.rightHalf(), v);
                return tree[k] = operator.applyAsLong(left, right);
            }
        } else{
            return tree[k];
        }
    }
    public void applyForPoint(int i, long v){
        tree[baseOfLeaf + i] = updateFunction.applyAsLong(tree[baseOfLeaf + i], collapseUpdateFunction.apply(v, 1));
    }

    public long query(int l, int r){
        return query(new Range(l, r), 0, new Range(0, leafs));
    }
    private long query(Range queryRange, int k, Range treeRange){
        evaluate(k, treeRange);
        if(!queryRange.crosses(treeRange)){
            return idElm;
        } else if(queryRange.contains(treeRange)){
            return tree[k];
        } else{
            long left = query(queryRange, left(k), treeRange.leftHalf());
            long right = query(queryRange, right(k), treeRange.rightHalf());
            return operator.applyAsLong(left, right);
        }
    }
    private void evaluate(int k, Range r){
        if(lazy[k] != defaultLazyValue) {
            if(!isLeaf(k)){
                lazy[left(k)] = mergeLazyFunction.applyAsLong(lazy[left(k)], lazy[k]);
                lazy[right(k)] = mergeLazyFunction.applyAsLong(lazy[right(k)], lazy[k]);
            }
            tree[k] = updateFunction.applyAsLong(tree[k], collapseUpdateFunction.apply(lazy[k], r.length()));
            lazy[k] = defaultLazyValue;
        }
    }
    private int minimumPowerOfTwo(int n){
        int i = 0;
        while(1 << ++i < n);
        return i;
    }
    private boolean isLeaf(int i){
        return i >= baseOfLeaf;
    }
    private int left(int k){
        return 2 * k + 1;
    }
    private int right(int k){
        return 2 * k + 2;
    }

    public String toString(){
        StringBuilder sb = new StringBuilder();
        for(int h = 0; h <= height; h++) {
            for(int i = (1 << h) - 1; i < (1 << (h + 1)) - 1; i++) {
                sb.append(tree[i]).append(" ");
            }
            sb.append('\n');
        }
        return sb.toString();
    }

    public static enum QueryFunctions{
        SUM((u, v) -> u + v, 0),
        // PRODUCT((u, v) -> u * v, 1),
        MAX((u, v) -> u > v ? u : v, Long.MIN_VALUE),
        MIN((u, v) -> u < v ? u : v, Long.MAX_VALUE),
        // GCD((u, v) -> gcd(u, v), 0),
        // LCM((u, v) -> lcm(u, v), 1),
        ;
        private final LongBinaryOperator queryFunction;
        private final long idElm;
        private QueryFunctions(LongBinaryOperator queryFunction, long idElm){
            this.queryFunction = queryFunction;
            this.idElm = idElm;
        }
        public LongBinaryOperator getQueryFunction(){
            return queryFunction;
        }
        public long getIdElm(){
            return idElm;
        }
    }
    public static enum UpdateFunctions{
        ADD((u, v) -> u + v, (u, v) -> u + v, (u, l) -> u * l, 0),
        SUB((u, v) -> u - v, (u, v) -> u + v, (u, l) -> u * l, 0),
        // MUL((u, v) -> u * v, (u, v) -> u * v, (u, l) -> u, 1),
        REWRITE((u, v) -> v, (u, v) -> v, (u, l) -> u, Long.MIN_VALUE + 1),
        ;
        private final LongBinaryOperator updateFunction;
        private final LongBinaryOperator mergeLazyFunction;
        private final BiFunction<Long, Integer, Long> collapseUpdateFunction;
        private final long defaultLazyValue;
        private UpdateFunctions(LongBinaryOperator updateFunction, LongBinaryOperator mergeLazyFunction, BiFunction<Long, Integer, Long> collapseUpdateFunction, long defaultLazyValue){
            this.updateFunction = updateFunction;
            this.mergeLazyFunction = mergeLazyFunction;
            this.collapseUpdateFunction = collapseUpdateFunction;
            this.defaultLazyValue = defaultLazyValue;
        }
        public LongBinaryOperator getUpdateFunction(){
            return updateFunction;
        }
        public LongBinaryOperator getMergeLazyFunction(){
            return mergeLazyFunction;
        }
        public BiFunction<Long, Integer, Long> getCollapseUpdateFunction(){
            return collapseUpdateFunction;
        }
        public long getDefaultLazyValue(){
            return defaultLazyValue;
        }
    }
    public static LazySegmentTree create(long[] t, QueryFunctions queryFunctionCode, UpdateFunctions updateFunctionCode){
        LongBinaryOperator operator = queryFunctionCode.getQueryFunction();
        long idElm = queryFunctionCode.getIdElm();
        LongBinaryOperator updateFunction = updateFunctionCode.getUpdateFunction();
        LongBinaryOperator mergeLazyFunction = updateFunctionCode.getMergeLazyFunction();
        BiFunction<Long, Integer, Long> collapseUpdateFunction = updateFunctionCode.getCollapseUpdateFunction();
        long defaultLazyValue = updateFunctionCode.getDefaultLazyValue();
        return new LazySegmentTree(t, operator, idElm, updateFunction, mergeLazyFunction, collapseUpdateFunction, defaultLazyValue);
    }
}

class LongQueue {
    private long[] a;
    private int head = 0, tail = 0;

    public LongQueue(int max) {
        a=new long[max+2];
    }

    public void addLast(long x) {
        a[tail++]=x;
    }

    public long pollFirst(){
        if (tail == head) {
            try {
                throw new Exception("no elements.");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return a[head++];
    }

    public long pollLast() {
        if (tail == head) {
            try {
                throw new Exception("no elements.");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return a[tail--];
    }

    public long getFirst() {
        return a[head];
    }

    public long getLast() {
        return a[tail - 1];
    }

    public int size() {
        return tail ^ head;
    }

    public void init() {
        head = 0;
        tail = 0;
    }
}


class LongUtil {
    public static long min(long... a) {
        long ret = Const.LINF;
        for (long c : a) {
            ret = Math.min(ret, c);
        }
        return ret;
    }

    public static long max(long... a) {
        long ret = -Const.LINF;
        for (long c : a) {
            ret = Math.max(ret, c);
        }
        return ret;
    }

    /**
     * Caluculate the ceil of a/b. Returns the smallest integer greater than or
     * equal to a/b while 'a/b' rounds fractional parts to ZERO.
     * 
     * @param a
     * @param b
     * @return the smallest integer greater than or equal to a/b
     */
    public static long cld(long a, long b) {
        if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
            if (b > 0) {
                return (a + b - 1) / b;
            } else {
                return (a + b + 1) / b;
            }
        } else {
            return a / b;
        }
    }

    /**
     * Caluculate the floor of a/b. Returns the largest integer less than or equal
     * to a/b while 'a/b' rounds fractional parts to ZERO.
     * 
     * @param a
     * @param b
     * @return the largest integer less than or equal to a/b
     */
    public static long fld(long a, long b) {
        if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
            return a / b;
        } else {
            if (b > 0) {
                return (a - b + 1) / b;
            } else {
                return (a - b - 1) / b;
            }
        }
    }

    public static long fold(LongBinaryOperator func, long a, long... b) {
        long ret = a;
        for (long c : b) {
            ret = func.applyAsLong(ret, c);
        }
        return ret;
    }
}


class MathUtil{
    /**
     * Enumarate primes less than n.
     * 
     * @param n
     * @return {@code ArrayList} that holds primes.
     */
    public static ArrayList<Integer> eratosthenes(int n) {
        int[] div = eratosthenesDivisors(n);
        ArrayList<Integer> result = new ArrayList<>();
        for (int i = 2; i <= n; i++) {
            if (div[i] == i) {
                result.add(i);
            }
        }
        return result;
    }
    /**
     * execute eratosthenes's prime-enumerate algorithm. a[i] holds the greatest
     * divisor of i. if a[i]=i, i is a prime number. This arrary enables you to
     * prime-factorize in O(log n) time. (<O(sqrt n)).
     * 
     * @param n
     * @return divisor array.
     */
    public static int[] eratosthenesDivisors(int n) {
        int[] divisors = new int[n + 1];
        if (n <= 0) {
            return null;
        }
        for (int i = 1; i <= n; i++) {
            if ((i & 1) != 0) {
                divisors[i] = i;
            } else {
                divisors[i] = 2;
            }
        }
        for (long i = 3; i <= n; i += 2) {
            if (divisors[(int) i] == (int) i) {
                for (long j = i * i; j <= n; j += (i << 1)) {
                    divisors[(int) j] = (int) i;
                }
            }
        }
        return divisors;
    }

    /**
     * Caluculate prime-factorization.
     * 
     * @param n
     * @return {@code HashMap} of {prime: index}
     */
    public static HashMap<Long, Integer> primeFactorization(long n) {
        HashMap<Long, Integer> primes = new HashMap<Long, Integer>();
        for (long p = 2; p * p <= n; p++) {
            int q = 0;
            while (n % p == 0) {
                n /= p;
                q++;
            }
            if (q > 0) {
                primes.put(p, q);
            }
        }
        if (n > 1) {
            primes.put(n, 1);
        }
        return primes;
    }

    private static HashMap<Long, Integer> lcm(HashMap<Long, Integer> amap, HashMap<Long, Integer> bmap) {
        if (amap.size() < bmap.size()) {
            return lcm(bmap, amap);
        }
        HashMap<Long, Integer> lcm = amap;
        for (Map.Entry<Long, Integer> e : bmap.entrySet()) {
            long prime = e.getKey();
            if (lcm.containsKey(prime)) {
                lcm.put(prime, Math.max(lcm.get(prime), e.getValue()));
            } else {
                lcm.put(prime, e.getValue());
            }
        }
        return lcm;
    }

    private static HashMap<Long, Integer> lcm(HashMap<Long, Integer> amap, long b) {
        HashMap<Long, Integer> bmap = primeFactorization(b);
        return lcm(amap, bmap);
    }

    public static HashMap<Long, Integer> lcm(long... a) {
        HashMap<Long, Integer> amap = new HashMap<>();
        for (long c : a) {
            amap = lcm(amap, c);
        }
        return amap;
    }
    public static long unsafeLCM(long a, long b) {
        return a * b / gcd(a, b);
    }

    /**
     * Caluculate the GCD of (a, b)/
     * 
     * @param a first value
     * @param b second value
     * @return GCD(a, b)
     */
    public static long gcd(long a, long b) {
        if (a < b) {
            return gcd(b, a);
        }
        if(b == 0) {
            return a;
        } else if(a == 0) {
            return b;
        }
        long r = a % b;
        while (r != 0) {
            a = b;
            b = r;
            r = a % b;
        }
        return b;
    }

    public static long gcd(long... a){
        long gcd = 0;
        for(long c:a){
            gcd = gcd(gcd, c);
        }
        return gcd;
    }

    /**
     * Return one of the solutions to {@code ax+by=gcd(a, b)}.
     * 
     * @return {@code x}, {@code y}, {@code gcd(a, b)}.
     * @param a a of ax+by=gcd(a, b).
     * @param b b of ax+by=gcd(a, b). class ReferenceLong is a reference type of long.
     */
    public static long[] extGCD(long a, long b) {
        ReferenceLong x = new ReferenceLong();
        ReferenceLong y = new ReferenceLong();
        long[] ret = new long[3];
        ret[2] = extGCD(a, b, x, y);
        ret[0] = x.v;
        ret[1] = y.v;
        return ret;
    }

    private static long extGCD(long a, long b, ReferenceLong x, ReferenceLong y) {
        if (b == 0) {
            x.v = 1;
            y.v = 0;
            return a;
        }
        long d = extGCD(b, a % b, y, x);
        y.v -= a / b * x.v;
        return d;
    }

    private static class ReferenceLong {
        long v = 0;
    }
}

class ModUtil{
    public static long mul(long... a) {
        long ret = 1;
        for (long c : a) {
            ret *= c;
            ret %= Const.MOD;
        }
        return ret;
    }

    public static long div(long a, long... b) {
        long ret = a;
        for (long c : b) {
            ret *= inv(c);
            ret %= Const.MOD;
        }
        return ret;
    }

    /**
     * Caluculate the value b s.t. a*b mod Const.MOD = 1.
     * 
     * @param a
     * @return inverse of a
     */
    public static long inv(long a) {
        long b = Const.MOD;
        long u = 1, v = 0;
        while (b >= 1) {
            long t = a / b;
            a -= t * b;
            long tmp1 = a;
            a = b;
            b = tmp1;
            u -= t * v;
            long tmp2 = u;
            u = v;
            v = tmp2;
        }
        u %= Const.MOD;
        return u >= 0 ? u : u + Const.MOD;
    }

    /**
     * Caluculate the combination nCr.
     * 
     * @param n left
     * @param r right
     * @return nCr
     */
    public static long comb(long n, long r) {
        if (n < r) {
            return 0;
        }
        r = Math.min(r, n - r);
        long res = 1;
        for (long d = 1; d <= r; d++) {
            res = div(mul(res, n--), d);
        }
        return res;
    }

    public static long[] fact(int n){
        long[] fact=new long[n+1];
        for(long i=0;i<=n;i++){
            if(i<=1){
                fact[(int)i]=1;
            } else{
                fact[(int)i]=mul(fact[(int)i-1], i);
            }
        }
        return fact;
    }
}


class Node{
    public int id;
    public ArrayList<Edge> edges;
    public long w;
    public int in;
    
    public Node(int id){
        this.id=id;
        this.edges = new ArrayList<Edge>();
    }
    public Node(int id, long w){
        this.id = id;
        this.w = w;
        this.edges = new ArrayList<>();
    }
    @Override public boolean equals(Object o){
        if(this == o) return true;
        if(! (o instanceof Node)) return false;
        Node n=(Node) o;
        return n.id == id;
    }
    @Override public int hashCode(){
        return id;
    }
}


@SuppressWarnings("unchecked")
class PolyLazySegmentTree<T, U>{
    private T[] tree;
    private U[] lazy;
    private T idElm;
    private U defaultLazyValue;
    private BiFunction<T, T, T> operator;
    private BiFunction<T, U, T> updateFunction;
    private BiFunction<U, U, U> mergeLazyFunction;
    private BiFunction<U, Integer, U> collapseUpdateFunction;
    private int size;
    private int leafs;
    private int height;
    private int baseOfLeaf;

    public PolyLazySegmentTree(T[] t, BiFunction<T, T, T> operator, T idElm, BiFunction<T, U, T> updateFunction, BiFunction<U, U, U> mergeLazyFunction , BiFunction<U, Integer, U> collapseUpdateFunction, U defaultLazyValue){
        int n = t.length;
        this.operator = operator;
        this.idElm = idElm;
        this.updateFunction = updateFunction;
        this.mergeLazyFunction = mergeLazyFunction;
        this.collapseUpdateFunction = collapseUpdateFunction;
        this.defaultLazyValue = defaultLazyValue;
        this.height = minimumPowerOfTwo(n);
        this.leafs = 1 << this.height;
        this.baseOfLeaf = this.leafs - 1;
        this.size = 2 * this.leafs - 1;
        this.lazy = (U[]) new Object[this.size];
        this.tree = (T[]) new Object[this.size];
        for(int i = size - 1; i >= 0; i--) {
            if(i >= baseOfLeaf + n) {
                this.tree[i] = this.idElm;
            } else if(isLeaf(i)) {
                this.tree[i] = t[i - baseOfLeaf];
            } else{
                this.tree[i] = operator.apply(this.tree[left(i)], this.tree[right(i)]);
            }
        }
    }

    public void applyForSegment(int l, int r, U v){
        applyForSegment(new Range(l, r), 0, new Range(0, leafs), v);
    }
    private T applyForSegment(Range queryRange, int k, Range treeRange, U v){
        evaluate(k, treeRange);
        if(queryRange.crosses(treeRange)) {
            if(queryRange.contains(treeRange)) {
                lazy[k] = mergeLazyFunction.apply(lazy[k], v);
                return updateFunction.apply(tree[k], collapseUpdateFunction.apply(lazy[k], treeRange.length()));
            } else {
                T left = applyForSegment(queryRange, left(k), treeRange.leftHalf(), v);
                T right = applyForSegment(queryRange, right(k), treeRange.rightHalf(), v);
                return tree[k] = operator.apply(left, right);
            }
        } else{
            return tree[k];
        }
    }
    public void applyForPoint(int i, U v){
        tree[baseOfLeaf + i] = updateFunction.apply(tree[baseOfLeaf + i], collapseUpdateFunction.apply(v, 1));
    }

    public T query(int l, int r){
        return query(new Range(l, r), 0, new Range(0, leafs));
    }
    private T query(Range queryRange, int k, Range treeRange){
        evaluate(k, treeRange);
        if(!queryRange.crosses(treeRange)){
            return idElm;
        } else if(queryRange.contains(treeRange)){
            return tree[k];
        } else{
            T left = query(queryRange, left(k), treeRange.leftHalf());
            T right = query(queryRange, right(k), treeRange.rightHalf());
            return operator.apply(left, right);
        }
    }
    private void evaluate(int k, Range r){
        if(lazy[k] != defaultLazyValue) {
            if(!isLeaf(k)){
                lazy[left(k)] = mergeLazyFunction.apply(lazy[left(k)], lazy[k]);
                lazy[right(k)] = mergeLazyFunction.apply(lazy[right(k)], lazy[k]);
            }
            tree[k] = updateFunction.apply(tree[k], collapseUpdateFunction.apply(lazy[k], r.length()));
            lazy[k] = defaultLazyValue;
        }
    }
    private int minimumPowerOfTwo(int n){
        int i = 0;
        while(1 << ++i < n);
        return i;
    }
    private boolean isLeaf(int i){
        return i >= baseOfLeaf;
    }
    private int left(int k){
        return 2 * k + 1;
    }
    private int right(int k){
        return 2 * k + 2;
    }

    private static class Range{
        private int left, right;
        Range(int left, int right){
            this.left = left;
            this.right = right;
        }
        boolean crosses(Range r){
            return this.left < r.right && r.left < this.right;
        }
        boolean contains(Range r){
            return this.left <= r.left && r.right <= this.right;
        }
        Range leftHalf(){
            return new Range(left, (left + right) / 2);
        }
        Range rightHalf(){
            return new Range((left + right) / 2, right);
        }
        int length(){
            return right - left;
        }
    }

    public String toString(){
        StringBuilder sb = new StringBuilder();
        for(int h = 0; h <= height; h++) {
            for(int i = (1 << h) - 1; i < (1 << (h + 1)) - 1; i++) {
                sb.append(tree[i]).append(" ");
            }
            sb.append('\n');
        }
        return sb.toString();
    }
}


class Prim{
    public static Edge[] prim(int n, Node[] nodes){
        HashSet<Integer> connected = new HashSet<>();
        connected.add(0);
        PriorityQueue<Edge> pq = new PriorityQueue<>((u, v)->Long.compare(u.cost, v.cost));
        for(Edge e: nodes[0].edges) pq.add(e);
        Edge[] ret = new Edge[n-1];
        int index = 0; 
        while(pq.size() > 0 && connected.size() < n){
            Edge e = pq.poll();
            for(int i = 0; i < 2; i++){
                int v = i==0 ? e.from : e.to;
                if(!connected.contains(v)){
                    ret[index++] = e;
                    connected.add(v);
                    for(Edge edge: nodes[v].edges){
                        if(!connected.contains(edge.from) || !connected.contains(edge.to)) pq.add(edge);
                    }
                    break;
                }
            }
        }
        return ret;
    }
}


class Range{
    public static final int MAX = +Const.IINF;
    public static final int MIN = -Const.IINF;
    public static final Range EMPTY = new Range(MAX, MAX);
    public static final Range WHOLE = new Range(MIN, MAX);

    public int left;
    public int right;

    public Range(int left, int right){
        if(left >= right){
            this.left = EMPTY.left;
            this.right = EMPTY.right;
        } else{
            this.left = left;
            this.right = right;
        }
    }
    public boolean crosses(Range r){
        return this.left < r.right && r.left < this.right;
    }
    public boolean contains(Range r){
        if(this.isEmpty()) return false;
        if(r.isEmpty()) return true;
        return this.left <= r.left && r.right <= this.right;
    }
    public Range leftHalf(){
        if(this.isEmpty()) return EMPTY;
        return new Range(left, (left + right) >> 1);
    }
    public Range rightHalf(){
        if(this.isEmpty()) return EMPTY;
        return new Range((left + right) >> 1, right);
    }
    public int length(){
        return right - left;
    }
    public Range intersection(Range r){
        if(!this.crosses(r)) return EMPTY;
        return new Range(Math.max(this.left, r.left), Math.min(this.right, r.right));
    }
    public ArrayList<Range> union(Range r){
        ArrayList<Range> union = new ArrayList<>();
        if(this.isEmpty()){
            union.add(r); 
        } else if(r.isEmpty()){
            union.add(this);
        } else if(this.crosses(r)){
            union.add(new Range(Math.min(this.left, r.left), Math.max(this.right, r.right)));
        } else {
            if(this.left < r.left){
                union.add(this);
                union.add(r);
            } else{
                union.add(r);
                union.add(this);
            }
        }
        return union;
    }
    public boolean isEmpty(){
        return this.equals(EMPTY);
    }
    public boolean nonEmpty(){
        return !this.isEmpty();
    }

    public static boolean crosses(Range r1, Range r2){
        return r1.crosses(r2);
    }
    public static Range leftHalf(Range r){
        return r.leftHalf();
    }
    public static Range rightHalf(Range r){
        return r.rightHalf();
    }
    public static int length(Range r){
        return r.length();
    }
    public static Range interSection(Range... rs){
        Range ret = WHOLE;
        for(Range r: rs) ret = ret.intersection(r);
        return ret;
    }
    public static ArrayList<Range> union(Range... rs){
        sort(rs, (u, v) -> Integer.compare(u.left, v.left));
        ArrayList<Range> union = new ArrayList<>();
        Range now = null;
        for(Range r: rs){
            if(r.isEmpty()) break;
            if(isNull(now)){
                now = r;
            } else{
                if(r.left <= now.right){
                    now.right = r.right;
                } else{
                    union.add(now);
                    now = r;
                }
            }
        }
        if(!isNull(now) && !now.equals(EMPTY)) union.add(now);
        if(union.isEmpty()) union.add(EMPTY);
        return union;
    }
    public static boolean isEmpty(Range r){
        return r.isEmpty();
    }
    public static boolean nonEmpty(Range r){
        return r.nonEmpty();
    }

    @Override
    public boolean equals(Object o){
        if(this == o) return true;
        if(!(o instanceof Range)) return false;
        Range r = (Range) o;
        return this.left == r.left && this.right == r.right; 
    }
    @Override
    public int hashCode(){
        return hash(left, right);
    }
    @Override
    public String toString(){
        return "["+left+", "+right+")";
    }
}


class RollingHash {
    private static final long mod = (1l << 61) - 1;
    private static final long mask31 = (1l << 31) - 1;
    private static final long mask30 = (1l << 30) - 1;

    private long base;
    private long[] pow;
    private int length;

    // hash[i] is the hash of substring[0, i). (i = 0, 1, ..., length)
    private long[] hash;

    public RollingHash(char[] ch) {
        length = ch.length;
        setBase();
        pow = new long[length + 1];
        powInit();
        hash = new long[length + 1];
        for(int i = 0; i < length; i++) hash[i + 1] = mod(mult(hash[i], base) + ch[i] + 1);
    }

    public long hash(int begin, int end) {
        long ret = hash[end] - mod(mult(hash[begin], pow[end - begin]));
        if (ret < 0) ret += mod;
        return ret;
    }

    // calc a*b mod 2^61-1 without overflow.
    // use the fact that 2^61 = 1 mod 2^61-1.
    private long mult(long a, long b) {
        // au is upper 30(=61-31) bits of a.
        // ad is lower 31 bits of a.
        // bu is upper 30(=61-31) bits of b.
        // bd is lower 31 bits of b.
        long au = a >> 31;
        long ad = a & mask31;
        long bu = b >> 31;
        long bd = b & mask31;
        // a*b = (au*2^31 + ad) * (bu*2^31 + bd)
        // a*b = au*bu*2^62 + (au*bd + ad*bu)*2^31 + ad*bd.

        // au*bu*2^62 = au*bu*2 (mod 2^61-1) because of 2^61 = 1 (mod 2^61-1)
        // au*bu*2 <= 2 * (2^30 - 1) * (2^30 - 1) = 2^61 - 2^32 + 2
        // mid := au*bd + ad*bu <= 2 * (2^30-1) * (2^31-1) = 2^62 - 3*2^31 + 2 <= 61bits
        // mid = midu*2^30 + midd.
        // midu is upper 31(=61-30) bits of b.
        // midd is lower 30 bits of b.
        // mid * 2^31 = midu*2^61 + midd*2^31 = midu + midd*2^31 <= 2^61 + 2^31
        // ad*bd <= (2^31 -1) * (2^31 - 1) = 2^62 - 2^32 + 1

        // (au*bu*2) + (midu+midd*2^31) + (ad*bd) <= 2^63 - 3*2^31 + 3 <= Long.MAX_VALUE
        long mid = au * bd + ad * bu;
        long midu = mid >> 30;
        long midd = mid & mask30;

        return (au * bu * 2) + (midu + (midd << 31)) + (ad * bd);
    }

    private long mod(long l) {
        l = (l & mod) + (l >> 61);
        while (l > mod) {
            l -= mod;
        }
        return l;
    }

    private void setBase(){
        Random r = new Random(System.currentTimeMillis());
        do base = r.nextLong(); while (base >= mod - 1 || base <= 6000);
    }

    private void powInit(){
        for (int i = 0; i < length; i++) {
            if (i == 0){
                pow[i] = 1;
            } else{
                pow[i] = mod(mult(pow[i - 1], base));
            }
        }
    }
}


class Search {
    // return the distance from 's' to other vertices as an array.
    public static int[] bfs(ArrayList<Integer>[] nodes, int s) {
        IntQueue q = new IntQueue(nodes.length);
        q.addLast(s);
        int n = nodes.length;
        int[] d = new int[n];
        fill(d, -1);
        d[s] = 0;
        while(q.size() > 0){
            int now = q.pollFirst();
            for(int next: nodes[now]){
                if(d[next] < 0){
                    d[next] = d[now] + 1;
                    q.addLast(next);
                }
            }
        }
        return d;
    }

    // return the shortest path from 's' to 't' as an array.
    // [s, a1, a2, ..., ak, t] => distance = array.length-1
    // if NO path from 's' to 't' exists, returns NULL.
    public static int[] bfs(ArrayList<Integer>[] nodes, int s, int t) {
        IntQueue q = new IntQueue(nodes.length + 1);
        q.addLast(s);
        int n = nodes.length;
        int[] d = new int[n];
        int[] prev = new int[n];
        prev[t] = -1;
        fill(d, -1);
        d[s] = 0;
        while(q.size() > 0){
            int now = q.pollFirst();
            for(int next: nodes[now]){
                if(d[next] < 0){
                    d[next] = d[now] + 1;
                    prev[next] = prev[s];
                    q.addLast(next);
                }
            }
        }
        if(prev[t] < 0) return null;
        int now = t;
        int[] path = new int[d[t] + 1];
        for (int i = 0; i <= d[t]; i++) {
            path[d[t] - i] = now;
            now = prev[now];
        }
        return path;
    }

    public static int[] _01bfs(Node[] nodes, int s){
        ArrayDeque<Integer> dq = new ArrayDeque<>();
        dq.add(s);
        int n = nodes.length;
        int[] d = new int[n];
        boolean[] visited=new boolean[n];
        fill(d, Const.IINF);
        d[s] = 0;
        while (dq.size() > 0) {
            int now = dq.pollFirst();
            if(visited[now]) continue;
            visited[now] = true;
            for (Edge e: nodes[now].edges) {
                int next = e.to;
                int cost = (int) e.cost;
                if (d[next] > d[now]) {
                    if (cost == 0) {
                        dq.addFirst(next);
                    } else {
                        dq.addLast(next);
                    }
                    d[next] = d[now] + cost;
                }
            }
        }
        return d;
    }
}


class SegmentTree{
    private long[] tree;
    private long idElm;
    private LongBinaryOperator operator;
    private int size;
    private int leafs;
    private int height;
    private int baseOfLeaf;

    public SegmentTree(long[] t, long idElm, LongBinaryOperator operator){
        int n = t.length;
        this.idElm = idElm;
        this.height = minimumPowerOfTwo(n);
        this.leafs = 1 << this.height;
        this.baseOfLeaf = this.leafs - 1;
        this.size = 2 * this.leafs - 1;
        this.tree = new long[this.size];
        for(int i = size - 1; i >= 0; i--) {
            if(i >= baseOfLeaf + n) {
                this.tree[i] = this.idElm;
            } else if(isLeaf(i)) {
                this.tree[i] = t[i - baseOfLeaf];
            } else{
                this.tree[i] = operator.applyAsLong(this.tree[left(i)], this.tree[right(i)]);
            }
        }
    }
    public void update(int i, int v){
        int index = i + baseOfLeaf;
        int parent = index;
        tree[index] = v;
        while(parent > 0){
            parent = (parent - 1) >> 1;
            tree[parent] = operator.applyAsLong(tree[left(parent)], tree[right(parent)]);
        }
    }
    // tree size=2^0+2^1+...+2^height=2^(height+1)-1
    public int size(){
        return size;
    }
    public int height(){
        return height;
    }
    public long query(int a, int b){
        return query(new Range(a, b), 0, new Range(0, leafs));
    }
    // tree[k] covers [l, r).
    private long query(Range queryRange, int k, Range treeRange){
        if(!queryRange.crosses(treeRange)){ // out of range
            return idElm;
        } else if(queryRange.contains(treeRange)){ //include range (+update)
            if(isLeaf(k)) return tree[k];
            else return tree[k] = operator.applyAsLong(tree[left(k)], tree[right(k)]);
        } else{
            long left=query(queryRange, left(k), treeRange.leftHalf());
            long right=query(queryRange, right(k), treeRange.rightHalf());
            return operator.applyAsLong(left, right);
        }
    }
    
    public String toString(){
        StringBuilder sb = new StringBuilder();
        for(int h = 0; h <= height; h++){
            for(int i = (1 << h) - 1; i < (1 << (h + 1))-1; i++){
                sb.append(tree[i]).append(" ");
            }
            sb.append('\n');
        }
        return sb.toString();
    }

    private int minimumPowerOfTwo(int n){
        int i = 0;
        while(1 << ++i < n);
        return i;
    }
    private boolean isLeaf(int i){
        return i >= baseOfLeaf;
    }
    private int left(int k){
        return 2 * k + 1;
    }
    private int right(int k){
        return 2 * k + 2;
    }
}


class SuffixArray {
    // sort suffixes of ch in O(n*log n).
    public static int[] suffixArray(char[] ch) {
        int n = ch.length;
        Integer[] order = new Integer[n];
        for (int i = 0; i < n; i++) {
            order[i] = n - i - 1;
        }
        Arrays.sort(order, (u, v) -> ch[u] - ch[v]);

        int[] suffixArray = new int[n];
        int[] classes = new int[n];

        for (int i = 0; i < n; i++) {
            suffixArray[i] = order[i];
            classes[i] = ch[i];
        }
        /*
         * suffixArray[i] is suffix on i'th position after sorting by first len
         * characters.
         */
        /*
         * classes[i] is equivalence class of the i'th suffix after sorting by first len
         * characters.
         */
        for (int len = 1; len < n; len *= 2) {
            int[] c = classes.clone();
            for (int i = 0; i < n; i++) {
                // condition that suffixArray[i-1]+len<n simulates 0-symbol at the end of the
                // string
                // a separate class is created for each suffix followed by simurated 0-symbol

                if (i == 0) {
                    classes[suffixArray[i]] = i;
                } else {
                    // judge the equivalence by deviding substring.
                    if (c[suffixArray[i - 1]] == c[suffixArray[i]] && suffixArray[i - 1] + len < n
                            && c[suffixArray[i - 1] + len / 2] == c[suffixArray[i] + len / 2]) {
                        classes[suffixArray[i]] = classes[suffixArray[i - 1]];
                    } else {
                        classes[suffixArray[i]] = i;
                    }
                }
            }
            // suffixes are already sorted by first len characters.
            // now sort suffixes by first len*2 characters.
            int[] count = new int[n];
            for (int i = 0; i < n; i++) {
                count[i] = i;
            }
            int[] s = suffixArray.clone();
            for (int i = 0; i < n; i++) {
                // s[i] is order of suffixes sorted by first len characters.
                // (s[i]-len) is order of suffixes sorted by second len characters.
                int s1 = s[i] - len;
                if (s1 >= 0) {
                    suffixArray[count[classes[s1]]++] = s1;
                }
            }
        }
        return suffixArray;
    }

    // sort rotation of S in O(n*log n).
    public static int[] rotationArray(char[] ch) {
        int n = ch.length;
        Integer[] order = new Integer[n];
        for (int i = 0; i < n; i++) {
            order[i] = i;
        }
        Arrays.sort(order, (u, v) -> ch[u] - ch[v]);

        int[] suffixArray = new int[n];
        int[] classes = new int[n];

        for (int i = 0; i < n; i++) {
            suffixArray[i] = order[i];
            classes[i] = ch[i];
        }
        /*
         * suffixArray[i] is suffix on i'th position after sorting by first len
         * characters.
         */
        /*
         * classes[i] is equivalence class of the i'th suffix after sorting by first len
         * characters.
         */
        for (int len = 1; len < n; len *= 2) {
            int[] c = classes.clone();
            for (int i = 0; i < n; i++) {
                // condition that suffixArray[i-1]+len<n simulates 0-symbol at the end of the
                // string
                // a separate class is created for each suffix followed by simurated 0-symbol

                if (i == 0) {
                    classes[suffixArray[i]] = i;
                } else {
                    // judge the equivalence by deviding substring.
                    if (c[suffixArray[i - 1]] == c[suffixArray[i]]
                            && c[(suffixArray[i - 1] + len / 2) % n] == c[(suffixArray[i] + len / 2) % n]) {
                        classes[suffixArray[i]] = classes[suffixArray[i - 1]];
                    } else {
                        classes[suffixArray[i]] = i;
                    }
                }
            }
            // suffixes are already sorted by first len characters.
            // now sort suffixes by first len*2 characters.
            int[] count = new int[n];
            for (int i = 0; i < n; i++) {
                count[i] = i;
            }
            int[] s = suffixArray.clone();
            for (int i = 0; i < n; i++) {
                // s[i] is order of suffixes sorted by first len characters.
                // (s[i]-len) is order of suffixes sorted by second len characters.
                int s1 = (s[i] - len + n) % n;
                suffixArray[count[classes[s1]]++] = s1;
            }
        }
        return suffixArray;
    }

    // longest common prefixes array in O(n)
    public static int[] lcp(int[] suffixArray, char[] ch){
        int n=suffixArray.length;
        int[] rank = new int[n];
        for(int i=0;i<n;i++){
            rank[suffixArray[i]]=i;
        }
        int[] lcp=new int[n-1];
        for(int i=0, h=0;i<n;i++){
            if(rank[i]<n-1){
                for(int j=suffixArray[rank[i]+1];Math.max(i, j)+h<ch.length&&ch[i+h]==ch[j+h];++h);
                lcp[rank[i]]=h;
                if(h>0){
                    h--;
                }
            }
        }
        return lcp;
    }
}

class TopologicalSort{
    static int[] topologicalSort(Node[] nodes){
        int n = nodes.length;
        int[] ret = new int[n];
        //for(Node node:nodes) for(Edge e:node.edges) nodes[e.id].in++;
        IntQueue zeros=new IntQueue(3*n);
        for(Node node: nodes) if(node.in == 0) zeros.addLast(node.id);
        int index = 0;
        while(zeros.size() > 0){
            int v = zeros.pollFirst();
            for(Edge e: nodes[v].edges){
                nodes[e.to].in--;
                if(nodes[e.to].in == 0) zeros.addLast(e.to);
            }
            ret[index++]=v;
        }
        if(index < n) return null;
        return ret;
    }
    
    // for example (n=9)
    // [1, 8] -> [2, 5, 6] -> [3, 7] -> [4] -> [9]
    // => length:5
    static int shortest(Node[] nodes){
        int n = nodes.length;
        int ret = 0;
        //for(Node node:nodes) for(Edge e:node.edges) nodes[e.id].in++;
        IntQueue zeros = new IntQueue(3 * n);
        for(Node node: nodes) if(node.in == 0) zeros.addLast(node.id);
        int num = zeros.size();
        while(zeros.size() > 0){
            int size = zeros.size();
            while(size > 0){
                int v = zeros.pollFirst();
                size--;
                for(Edge e: nodes[v].edges){
                    int u = e.to;
                    if(--nodes[u].in == 0){
                        zeros.addLast(u);
                        num++;
                    }
                }
            }
            ret++;
        }
        if(num < n) return -1;
        return ret;
    }
}

class TwoDimensionsBinaryIndexedTree{
    private int[][] tree;
    private int[][] originalArray;
    private int n, m;

    public TwoDimensionsBinaryIndexedTree(int[][] array){
        this.originalArray = array.clone();
        this.n = array.length;
        this.m = array[0].length;
        this.tree = new int[n+1][m+1];
        init();
    }
    public TwoDimensionsBinaryIndexedTree(int initial, int n, int m){
        this.originalArray = new int[n][m];
        this.n = n;
        this.tree = new int[n+1][m+1];
        for(int i = 0; i < n; i++){
            for(int j = 0; j < m; j++){
                originalArray[i][j] = initial;
            }
        }
        init();
    }
    public TwoDimensionsBinaryIndexedTree(int n, int m){
        this(0, n, m);
    }
    private void init(){
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= m; j++){
                tree[i][j] += originalArray[i-1][j-1];
                int pi=i + (-i & i);
                int pj=j + (-j & j);
                if(pi <= n && pj <= m){
                    tree[pi][pj] += tree[i][j];
                } else if(pi <= n){
                    tree[pi][j] += tree[i][j];
                } else if(pj <= m){
                    tree[i][pj] += tree[i][j];
                }
            }
        }
    }

    /**
     * Calculate the sum of range (l, r] in array (1-indexed).
     * @param l left border (open)
     * @param r right border (closed)
     * @return sum of range (l, r] in array (1-indexed).
     */
    public int sum(int il, int ir, int jl, int jr){
        return sum(ir, jr) - sum(il, jl);
    }
    private int sum(int i, int j){
        int ret=0;
        for(; i > 0; i -= -i & i){
            for(; j > 0; j -= -j & j){
                ret += tree[i][j];
            }
        }
        return ret;
    }

    /**
     * add v to array[i] and update BIT.
     * @param i index of array (1-indexed)
     * @param v adding value
     */
    public void add(int i, int j, int v){
        originalArray[i-1][j-1] += v;
        for(; i <= n; i += -i & i){
            for(; j <= m; j += -j & j){
                tree[i][j] += v;
            }
        }
    }

    /**
     * update the value of array[i] to v and update BIT.
     * @param i index of array (1-indexed)
     * @param v adding value
     */
    public void update(int i, int j, int v){
        add(i, j, v - originalArray[i-1][j-1]);
        originalArray[i-1][j-1] = v;
    }
}


class UnionFindTree {
    private int[] parent;
    private int[] rank;
    private int[] size;
    private int groups;
    public UnionFindTree(int n){
        this.parent = new int[n];
        this.rank = new int[n];
        this.size = new int[n];
        this.groups = n;
        fill(this.size, 1);
        for(int i = 0; i < n; i++) parent[i] = i;
    }
    public int root(int x){
        if(parent[x] == x) return x;
        return parent[x] = root(parent[x]);
    }
    public boolean isSame(int x, int y){
        return root(x) == root(y);
    }
    public void unite(int x, int y){
        int xr = root(x);
        int yr = root(y);
        if(xr == yr) return;
        if(rank[xr] < rank[yr]){
            parent[xr] = yr;
            size[yr] += size[xr];
        }
        else{
            parent[yr] = xr;
            size[xr] += size[yr];
            if(rank[xr] == rank[yr]) rank[xr]++;
        }
        groups--;
    }
    public int size(int x){
        return size[root(x)];
    }
    public int groups(){
        return groups;
    }
}
