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;

/**
 * Created by Arkady on 26.05.2019.
 */
public class B {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int m = in.nextInt();
        int[][] a = new int[m][2];
        for (int i = 0; i < m; i++) {
            a[i][0] = in.nextInt();
            a[i][1] = in.nextInt();
        }
        boolean ans = false;
        if(m == 1) {
            ans = true;
        }
        int x = -1;
        int y = -1;

        x = a[0][0];
        for (int i = 1; i < m; i++) {
            boolean pargood = false;
            if (a[i][0] == x || a[i][0] == y) {
                pargood = true;
            }
            if (a[i][1] == x || a[i][1] == y) {
                pargood = true;
            }
            if (!pargood) {
                if (y == -1) {
                    y = a[i][0];
                } else {
                    i = m;
                }
            }
            if (i == m - 1) {
                ans = true;
            }
        }


        y = -1;
        for (int i = 1; i < m; i++) {
            boolean pargood = false;
            if (a[i][0] == x || a[i][0] == y) {
                pargood = true;
            }
            if (a[i][1] == x || a[i][1] == y) {
                pargood = true;
            }
            if (!pargood) {
                if (y == -1) {
                    y = a[i][1];
                } else {
                    i = m;
                }
            }
            if (i == m - 1) {
                ans = true;
            }
        }

        y = -1;
        x = a[0][1];
        for (int i = 1; i < m; i++) {
            boolean pargood = false;
            if (a[i][0] == x || a[i][0] == y) {
                pargood = true;
            }
            if (a[i][1] == x || a[i][1] == y) {
                pargood = true;
            }
            if (!pargood) {
                if (y == -1) {
                    y = a[i][0];
                } else {
                    i = m;
                }
            }
            if (i == m - 1) {
                ans = true;
            }
        }

        y = -1;
        for (int i = 1; i < m; i++) {
            boolean pargood = false;
            if (a[i][0] == x || a[i][0] == y) {
                pargood = true;
            }
            if (a[i][1] == x || a[i][1] == y) {
                pargood = true;
            }
            if (!pargood) {
                if (y == -1) {
                    y = a[i][1];
                } else {
                    i = m;
                }
            }
            if (i == m - 1) {
                ans = true;
            }
        }

        if (ans) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }

    }
}
