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.lang.reflect.Array;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int m = scanner.nextInt();
        boolean[] used = new boolean[m];
        Pair[] pairs = new Pair[m];
        for (int i = 0 ; i < m ; ++i) {
            int a = scanner.nextInt() - 1;
            int b = scanner.nextInt() - 1;
            pairs[i] = new Pair(a, b);
        }
        int x = pairs[0].a;
        int xFound = 0;
        for (int i = 0 ; i < m ; ++i) {
            if (pairs[i].a == x || pairs[i].b == x) {
                xFound++;
                used[i] = true;
            }
        }
        if (xFound == m) {
            System.out.println("YES");
            return;
        }
        int yFound = 0;
        Pair woX = null;
        for (int i = 0 ; i < m ; ++i) {
            if (!used[i]) {
                woX = pairs[i];
                break;
            }
        }
        int fY = woX.a;
        for (int i = 0 ; i < m ; ++i) {
            if (!used[i]) {
                if (pairs[i].a == fY || pairs[i].b == fY) yFound++;
            }
        }
        if (yFound + xFound == m) {
            System.out.println("YES");
            return;
        }
        yFound = 0;
        int sY = woX.b;
        for (int i = 0 ; i < m ; ++i) {
            if (!used[i]) {
                if (pairs[i].a == sY || pairs[i].b == sY) yFound++;
            }
        }
        if (yFound + xFound == m) {
            System.out.println("YES");
            return;
        }
        for (int i = 0 ; i < m ; ++i) used[i] = false;
        x = pairs[0].b;
        xFound = 0;
        for (int i = 0 ; i < m ; ++i) {
            if (pairs[i].a == x || pairs[i].b == x) {
                xFound++;
                used[i] = true;
            }
        }
        if (xFound == m) {
            System.out.println("YES");
            return;
        }
        yFound = 0;
        woX = null;
        for (int i = 0 ; i < m ; ++i) {
            if (!used[i]) {
                woX = pairs[i];
                break;
            }
        }
        fY = woX.a;
        for (int i = 0 ; i < m ; ++i) {
            if (!used[i]) {
                if (pairs[i].a == fY || pairs[i].b == fY) yFound++;
            }
        }
        if (yFound + xFound == m) {
            System.out.println("YES");
            return;
        }
        yFound = 0;
        sY = woX.b;
        for (int i = 0 ; i < m ; ++i) {
            if (!used[i]) {
                if (pairs[i].a == sY || pairs[i].b == sY) yFound++;
            }
        }
        if (yFound + xFound == m) {
            System.out.println("YES");
            return;
        }
        System.out.println("NO");

    }

    private static final class Pair{
        int a;
        int b;
        Pair(int a, int b) {
            this.a = a;
            this.b = b;
        }
    }
}
