Vasya has two arrays A and B of lengths n and m, respectively.

He can perform the following operation arbitrary number of times (possibly zero): he takes some consecutive subsegment of the array and replaces it with a single element, equal to the sum of all elements on this subsegment. For example, from the array [1, 10, 100, 1000, 10000] Vasya can obtain array [1, 1110, 10000], and from array [1, 2, 3] Vasya can obtain array [6].

Two arrays A and B are considered equal if and only if they have the same length and for each valid i A_i = B_i.

Vasya wants to perform some of these operations on array A, some on array B, in such a way that arrays A and B become equal. Moreover, the lengths of the resulting arrays should be maximal possible.

Help Vasya to determine the maximum length of the arrays that he can achieve or output that it is impossible to make arrays A and B equal.

Input

The first line contains a single integer n~(1 ≤ n ≤ 3 ⋅ 10^5) — the length of the first array.

The second line contains n integers a_1, a_2, ⋅⋅⋅, a_n~(1 ≤ a_i ≤ 10^9) — elements of the array A.

The third line contains a single integer m~(1 ≤ m ≤ 3 ⋅ 10^5) — the length of the second array.

The fourth line contains m integers b_1, b_2, ⋅⋅⋅, b_m~(1 ≤ b_i ≤ 10^9) - elements of the array B.

Output

Print a single integer — the maximum length of the resulting arrays after some operations were performed on arrays A and B in such a way that they became equal.

If there is no way to make array equal, print "-1".

Examples

Input

5
11 2 3 5 7
4
11 7 3 7


Output

3


Input

2
1 2
1
100


Output

-1


Input

3
1 2 3
3
1 2 3


Output

3
import java.io.*;
import java.math.*;
import java.util.*;

public class Main {
    static PrintWriter pw;
    static Scanner sc;
    static long ceildiv(long x, long y) { return (x+y-1)/y; }
    static int mod(long x, int m) { return (int)((x%m+m)%m); }
    static void put(HashMap<Long, Integer> map, long p){if(map.containsKey(p)) map.replace(p, map.get(p)+1); else map.put(p, 1); }
    static void rem(TreeMap<Integer, Integer> map, Integer p){ if(map.get(p)==1) map.remove(p);else map.replace(p, map.get(p)-1); }
    static void printf(double x, int dig){ String s="%."+dig+"f"; pw.printf(s, x); }
    static int Int(boolean x){ return x?1:0; }
    static final int inf=(int)1e9, mod=998244353;
    static final long infL=inf*1l*inf;
    static final double eps=1e-9;
    public static long gcd(long x, long y) { return y==0? x: gcd(y, x%y); }
    public static void main(String[] args) throws IOException{
        sc=new Scanner(System.in);
        pw=new PrintWriter(System.out);
//        int t=sc.nextInt();
//        while(t-->0)
            testcase();
        pw.close();
    }
    static void testcase() throws IOException{
        int n=sc.nextInt(), a[]=sc.nextArr(n);
        int m=sc.nextInt(), b[]=sc.nextArr(m);
        long sum=0;
        for (int i = 0; i < n; i++)
            sum+=a[i];
        for (int i = 0; i < m; i++)
            sum-=b[i];
        if(sum!=0){
            pw.println(-1);
            return;
        }
        int ans=0;
        long x=a[0], y=b[0];
        for(int i=0, j=0; i<n && j<m; ){
            if(x==y){
                ans++;
                if(j<m-1){
                    y+=b[++j];
                    x+=a[++i];
                }else{
                    break;
                }
            }else if(x>y){
                y+=b[++j];
            }else{
                x+=a[++i];
            }
        }
        pw.println(ans);
    }
    static void printArr(int[] arr) {
        for (int i = 0; i < arr.length - 1; i++)
            pw.print(arr[i] + " ");
        pw.println(arr[arr.length - 1]);
    }
    static void printArr(long[] arr) {
        for (int i = 0; i < arr.length - 1; i++)
            pw.print(arr[i] + " ");
        pw.println(arr[arr.length - 1]);
    }
    static void printArr(double[] arr) {
        for (int i = 0; i < arr.length - 1; i++)
            pw.print(arr[i] + " ");
        pw.println(arr[arr.length - 1]);
    }
    static void printArr(Integer[] arr) {
        for (int i = 0; i < arr.length; i++)
            pw.print(arr[i] + " ");
        pw.println();
    }
    static void printArr(ArrayList<Integer> list) {
        for (int i = 0; i < list.size(); i++)
            pw.print(list.get(i)+" ");
        pw.println();
    }
    static void printArr(boolean[] arr) {
        StringBuilder sb=new StringBuilder();
        for(boolean b: arr)
            sb.append(Int(b));
        pw.println(sb);
    }
    static class Scanner {
        StringTokenizer st;
        BufferedReader br;
        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public Scanner(FileReader r) {
            br = new BufferedReader(r);
        }

        public String next() throws IOException {
            while (st == null || !st.hasMoreTokens())
                st = new StringTokenizer(br.readLine());
            return st.nextToken();
        }

        public int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        public long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        public String nextLine() throws IOException {
            return br.readLine();
        }

        public double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
        public int[] nextDigits() throws IOException{
            String s=nextLine();
            int[] arr=new int[s.length()];
            for(int i=0; i<arr.length; i++)
                arr[i]=s.charAt(i)-'0';
            return arr;
        }
        public int[] nextArr(int n) throws IOException {
            int[] arr = new int[n];
            for (int i = 0; i < arr.length; i++)
                arr[i] = nextInt();
            return arr;
        }
        public Integer[] nextsort(int n) throws IOException{
            Integer[] arr=new Integer[n];
            for(int i=0; i<n; i++)
                arr[i]=nextInt();
            return arr;
        }
        public Pair nextPair() throws IOException{
            return new Pair(nextInt(), nextInt());
        }
        public long[] nextLongArr(int n) throws IOException{
            long[] arr=new long[n];
            for (int i = 0; i < n; i++)
                arr[i]=sc.nextLong();
            return arr;
        }
        public Pair[] nextPairArr(int n) throws IOException{
            Pair[] arr=new Pair[n];
            for(int i=0; i<n; i++)
                arr[i]=nextPair();
            return arr;
        }
        public boolean ready() throws IOException {
            return br.ready();
        }
    }
    static class Pair implements Comparable<Pair>{
        int x;
        int y;
        public Pair(int x, int y) {
            this.x=x;
            this.y=y;
        }
        public boolean contains(int a){
            return x==a || y==a;
        }
        public int hashCode() {
            return (this.x*1000000000+this.y);
        }
        public int compareTo(Pair p){
            if(x==p.x)
                return y-p.y;
            return x-p.x;
        }
        public boolean equals(Object obj) {
            if (obj == null) {
                return false;
            }
            if (this.getClass() != obj.getClass()) {
                return false;
            }
            Pair p = (Pair) obj;
            return this.x==p.x && this.y==p.y;
        }
        public Pair clone(){
            return new Pair(x, y);
        }
        public String toString(){
            return this.x+" "+this.y;
        }
        public void add(Pair p){
            x+=p.x;
            y+=p.y;
        }
        public Pair negative(){
            return new Pair(-x, -y);
        }
    }
    static class LP implements Comparable<LP>{
        long x, y;
        public LP(long a, long b){
            x=a;
            y=b;
        }
        public void add(LP p){
            x+=p.x;
            y+=p.y;
        }
        public boolean equals(LP p){
            return p.x==x && y==p.y;
        }
        public String toString(){
            return this.x+" "+this.y;
        }
        public int compareTo(LP p){
            int a=Long.compare(x, p.x);
            if(a!=0)
                return a;
            return Long.compare(y, p.y);
        }
    }
    static class Triple implements Comparable<Triple>{
        int x, y, z;
        public Triple(int a, int b, int c){
            x=a;
            y=b;
            z=c;
        }
        public int compareTo(Triple t){
            if(this.y!=t.y)
                return y-t.y;
            return x-t.x;
        }
        public String toString(){
            return x+" "+y+" "+z;
        }
    }
}