Toad Ivan has m pairs of integers, each integer is between 1 and n, inclusive. The pairs are (a_1, b_1), (a_2, b_2), …, (a_m, b_m). 

He asks you to check if there exist two integers x and y (1 ≤ x < y ≤ n) such that in each given pair at least one integer is equal to x or y.

Input

The first line contains two space-separated integers n and m (2 ≤ n ≤ 300 000, 1 ≤ m ≤ 300 000) — the upper bound on the values of integers in the pairs, and the number of given pairs.

The next m lines contain two integers each, the i-th of them contains two space-separated integers a_i and b_i (1 ≤ a_i, b_i ≤ n, a_i ≠ b_i) — the integers in the i-th pair.

Output

Output "YES" if there exist two integers x and y (1 ≤ x < y ≤ n) such that in each given pair at least one integer is equal to x or y. Otherwise, print "NO". You can print each letter in any case (upper or lower).

Examples

Input


4 6
1 2
1 3
1 4
2 3
2 4
3 4


Output


NO


Input


5 4
1 2
2 3
3 4
4 5


Output


YES


Input


300000 5
1 2
1 2
1 2
1 2
1 2


Output


YES

Note

In the first example, you can't choose any x, y because for each such pair you can find a given pair where both numbers are different from chosen integers.

In the second example, you can choose x=2 and y=4.

In the third example, you can choose x=1 and y=2.
import java.util.*;
import java.io.*;
import static java.lang.Math.*;
public class MainS {
    static final long MOD = 1_000_000_007, INF = 1_000_000_000_000_000_000L;
    static final int INf = 1_000_000_000;
    static FastReader reader;
    static PrintWriter writer;

    public static void main(String[] args) {
        Thread t = new Thread(null, new O(), "Integer.MAX_VALUE", 100000000);
        t.start();
    }

    static class O implements Runnable {
        public void run() {
            try {
                magic();
            } catch (Exception e) {
                e.printStackTrace();
                System.exit(1);
            }
        }
    }

    public static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

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

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

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    }
    static int n, tree[];
    static void magic() throws IOException {
        reader = new FastReader();
        writer = new PrintWriter(System.out, true);
        n = reader.nextInt();
        int m = reader.nextInt();
        int sz = (int)pow(2,ceil(log(n+1)/log(2))+1);
        tree = new int[sz];
        ArrayList<Pair> list[] = new ArrayList[n+1];
        for(int i=1;i<=n;++i) {
            list[i] = new ArrayList<>();
        }
        for(int i=0;i<m;++i) {
            int x = reader.nextInt(), y = reader.nextInt();
            int min = min(x,y), max = max(x,y);
            list[min].add(new Pair(x,y));
            list[max].add(new Pair(x,y));
            update(max, 1);
            update(min , 1);
        }

        for(int i=1;i<=n;++i) {
            for(Pair p : list[i]) {
                int min = min(p.x, p.y), max = max(p.x, p.y);
                update(max, -1);
                update(min, -1);
            }
            if(query(0,n)==(m-list[i].size())) {
                writer.println("YES");
                System.exit(0);
            }
            for(Pair p : list[i]) {
                int min = min(p.x, p.y), max = max(p.x, p.y);
                update(max, 1);
                update(min, 1);
            }
        }
        writer.println("NO");
    }
    static void update(int treein,int low,int high,int idx,int val)
    {
        if(low==high)
            tree[treein] += val;
        else
        {
            int mid = (low+high)>>1;
            if(idx<=mid)
                update(2*treein,low,mid,idx,val);
            else update(2*treein+1,mid+1,high,idx,val);
            tree[treein] = max(tree[2*treein],tree[2*treein+1]);
        }
    }
    static int query(int treein,int low,int high,int l,int r)
    {
        if(l<=low && high<=r)
            return tree[treein];
        if(low>r || high<l)
            return 0;
        int mid = (low+high)>>1;
        return max(query(2*treein,low,mid,l,r),query(2*treein+1,mid+1,high,l,r));
    }
    static int query(int l,int r)
    {
        return query(1,0,n,l,r);
    }
    static void update(int idx,int val)
    {
        update(1,0,n,idx,val);
    }
    static class Pair implements Comparable<Pair>
    {
        int x,y;
        Pair(int x,int y)
        {
            this.x=x;
            this.y=y;
        }
        public int compareTo(Pair other)
        {
            if(this.x!=other.x)
                return this.x-other.x;
            return this.y-other.y;
        }
        public String toString()
        {
            return "("+x+","+y+")";
        }
    }
}