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.lang.*;
import java.io.*;

//           THIS TEMPLATE MADE BY AKSH BANSAL.

public class Solution {
    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;
        }
    }

    public static void main(String[] args) throws IOException {
        FastReader sc = new FastReader();
        PrintWriter out = new PrintWriter(System.out);
        // ________________________________

        // int t = sc.nextInt();
        // StringBuilder output = new StringBuilder();

        // while (t-- > 0) {
        //     int n = sc.nextInt();
        //     output.append(solver(n)).append("\n");
        // }

        // out.println(output);
        // _______________________________

        int n = sc.nextInt();
        int m = sc.nextInt();
        int[][] graph = new int[m][2];
        for(int i=0;i<m;i++){
            graph[i][0] = sc.nextInt();
            graph[i][1] = sc.nextInt();
        }
        out.println(solver(n,m,graph));
        // ________________________________
        out.flush();
    }

    public static String solver(int n, int m, int[][] graph) {
        if(m<=2 || n<=2)return "YES";
        for(int cur: graph[0]){
            int[] presentWhenCurAbsent = new int[n+1];
            int absent = 0;
            for(int i=1;i<m;i++){
                if(graph[i][0]!=cur && graph[i][1]!=cur){
                    absent++;
                    presentWhenCurAbsent[graph[i][0]]++;
                    presentWhenCurAbsent[graph[i][1]]++;
                }
            }
            int max = -1;
            for(int i=1;i<=n;i++){
                max = Math.max(max,presentWhenCurAbsent[i]);
            }
            if(max==absent){
                return "YES";
            }
        }
        return "NO";
    }
}