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

import static java.lang.Math.*;

public class Main {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    PrintWriter pw = new PrintWriter(System.out);

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

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

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

    public static void main(String[] args) throws IOException {
        new Main().run();
    }

    void run() throws IOException {
        int n, m;
        n = nextInt();
        m = nextInt();
        int[][] a = new int[m][2];
        for (int i = 0; i < m; i++) {
            a[i][0] = nextInt();
            a[i][1] = nextInt();
        }
        int x = a[0][0];
        int y = a[0][1];
        int b = 0, c = 0;
        boolean e = false;
        for (int i = 1; i < m; i++) {
            if (a[i][0] != x && a[i][1] != x && a[i][0] != y && a[i][1] != y) {
                b = a[i][0];
                c = a[i][1];
                e = true;
                break;
            }
        }
        if (!e) {
            pw.print("YES");
            pw.close();
            return;
        }
        int r = 0;
        while (r < m && (a[r][0] == x || a[r][1] == x || a[r][0] == b || a[r][1] == b)) {
            r++;
        }
        if (r == m) {
            pw.print("YES");
            pw.close();
            return;
        }
        r = 0;
        while (r < m && (a[r][0] == x || a[r][1] == x || a[r][0] == c || a[r][1] == c)) {
            r++;
        }
        if (r == m) {
            pw.print("YES");
            pw.close();
            return;
        }
        r = 0;
        while (r < m && (a[r][0] == y || a[r][1] == y || a[r][0] == b || a[r][1] == b)) {
            r++;
        }
        if (r == m) {
            pw.print("YES");
            pw.close();
            return;
        }
        r = 0;
        while (r < m && (a[r][0] == y || a[r][1] == y || a[r][0] == c || a[r][1] == c)) {
            r++;
        }
        if (r == m) {
            pw.print("YES");
            pw.close();
            return;
        }
        pw.print("NO");
        pw.close();
    }
}

