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.*;

public class BB {
    public static void main(String[] args) {
        FastScanner scanner = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);
        int N = scanner.nextInt();
        int M = scanner.nextInt();
        Pair[] pairs = new Pair[M];
        for(int i = 0; i < M; i++) {
            pairs[i] = new Pair(scanner.nextInt(), scanner.nextInt());
        }
        int cur = pairs[0].a;
        int cnt = 0;
        boolean[] good = new boolean[M];
        for(int i = 0; i < M; i++) {
            if (pairs[i].a == cur || pairs[i].b == cur) {
                cnt++;
                good[i] = true;
            }
        }
        if (cnt == M) {
            System.out.println("YES");
            return;
        }
        for(int i =0; i < M; i++) {
            if (!good[i]) {
                cur = pairs[i].a;
                int prevCnt = cnt;
                for(int j = i; j < M; j++) {
                    if (!good[j] && (pairs[j].a == cur || pairs[j].b == cur)) {
                        cnt++;
                    }
                }
                if (cnt == M) {
                    System.out.println("YES");
                    return;
                }
                cur = pairs[i].b;
                for(int j = i; j < M; j++) {
                    if (!good[j] &&(pairs[j].a == cur || pairs[j].b == cur)) {
                        prevCnt++;
                    }
                }
                if (prevCnt == M) {
                    System.out.println("YES");
                    return;
                }
                break;
            }
        }
        cur = pairs[0].b;
        cnt = 0;
        good = new boolean[M];
        for(int i = 0; i < M; i++) {
            if (pairs[i].a == cur || pairs[i].b == cur) {
                cnt++;
                good[i] = true;
            }
        }
        if (cnt == M) {
            System.out.println("YES");
            return;
        }
        for(int i =0; i < M; i++) {
            if (!good[i]) {
                cur = pairs[i].a;
                int prevCnt = cnt;
                for(int j = i; j < M; j++) {
                    if (!good[j] && (pairs[j].a == cur || pairs[j].b == cur)) {
                        cnt++;
                    }
                }
                if (cnt == M) {
                    System.out.println("YES");
                    return;
                }
                cur = pairs[i].b;
                for(int j = i; j < M; j++) {
                    if (!good[j] &&(pairs[j].a == cur || pairs[j].b == cur)) {
                        prevCnt++;
                    }
                }
                if (prevCnt == M) {
                    System.out.println("YES");
                    return;
                }
                break;
            }
        }
        out.println("NO");
        out.flush();
    }
    
    public static boolean check(Pair[] pairs, Pair check) {
        for(int i = 0; i < pairs.length; i++) {
            if (pairs[i].a != check.a && pairs[i].a != check.b && pairs[i].b != check.a && pairs[i].b != check.b) return false;
        }
        return true;
    }
    
    public static class Pair {
        int a,b;
        public Pair(int aa, int bb) {
            a = Math.min(aa, bb); b = Math.max(aa,bb);
        }
    }
    
    public static class FastScanner {
        BufferedReader br;
        StringTokenizer st;
        
        public FastScanner(Reader in) {
            br = new BufferedReader(in);
        }
        
        public FastScanner() {
            this(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 readNextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
        
        int[] readIntArray(int n) {
            int[] a = new int[n];
            for (int idx = 0; idx < n; idx++) {
                a[idx] = nextInt();
            }
            return a;
        }
    }
}
