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.
//package com.krakn.CF.B.B1169;

import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) {
        FastReader fr = new FastReader();

        int n = fr.nextInt();
        int m = fr.nextInt();

        int[][] arr = new int[m][2];
        for (int i = 0; i < m; i++) {
            arr[i][0] = fr.nextInt();
            arr[i][1] = fr.nextInt();
        }

        int z = 0;
        int a = arr[0][0];
        while (z < 2) {
            List<Integer> queue = new ArrayList<>();
            for (int i = 0; i < m; i++) {
                if (a != arr[i][0] && a != arr[i][1]) {
                    queue.add(i);
                }
            }
            if (queue.size() > 0) {
                int b = arr[queue.get(0)][0];
                boolean f = true;
                for (int i = 0; i < queue.size(); i++) {
                    if (b != arr[queue.get(i)][0] && b != arr[queue.get(i)][1]) {
                        f = false;
                        break;
                    }
                }

                if (f) {
                    System.out.println("YES");
                    return;
                }

                b = arr[queue.get(0)][1];
                f = true;
                for (int i = 0; i < queue.size(); i++) {
                    if (b != arr[queue.get(i)][0] && b != arr[queue.get(i)][1]) {
                        f = false;
                        break;
                    }
                }

                if (f) {
                    System.out.println("YES");
                    return;
                }
            } else {
                System.out.println("YES");
                return;
            }

            a = arr[0][1];
            z++;
        }

        System.out.println("NO");
    }

    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;
        }
    }
}
