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.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int max = scanner.nextInt();
        int n = scanner.nextInt();

        int[][] data = new int[n][2];
        for (int i = 0; i < n; i++) {
            data[i][0] = scanner.nextInt();
            data[i][1] = scanner.nextInt();
        }


        int a = data[0][0];
        int b = data[0][1];

        int[] sa = sugest(data, a);
        int[] sb = sugest(data, b);


        if (
                test(data, a, sa[0]) ||
                        test(data, a, sa[1]) ||
                        test(data, b, sb[0]) ||
                        test(data, b, sb[1])
        )
            System.out.println("YES");
        else
            System.out.println("NO");

    }

    static int[] sugest(int[][] data, int x) {
        for (int[] datum : data) {
            int a = datum[0];
            int b = datum[1];

            boolean ok = a == x || b == x;
            if (!ok)
                return datum;
        }

        return data[0];

    }

    static boolean test(int[][] data, int x, int y) {
        for (int[] datum : data) {
            int a = datum[0];
            int b = datum[1];

            boolean ok = a == x || a == y || b == x || b == y;
            if (!ok)
                return false;
        }

        return true;
    }
}
