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 PairsB {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        final int n = scanner.nextInt();
        final int m = scanner.nextInt();
        int[][] data = new int[m][2];

        for (int i = 0; i < m; i++) {
            data[i][0] = scanner.nextInt();
            data[i][1] = scanner.nextInt();
        }
        if(pairsExist(data[0][0], data)){
            System.out.println("YES");
        }else if(pairsExist(data[0][1], data)){
            System.out.println("YES");
        }else{
            System.out.println("NO");
        }
        scanner.close();

    }

    private static boolean pairsExist(int x, int[][] data){
        int y1=-1;
        int y2=-1;
        int countX=1;
        int countY1=0;
        int countY2=0;
        for (int j = 1; j < data.length ; j++) {
            if(data[j][0]==x||data[j][1]==x){
                countX++;
                continue;
            }
            if(y1==-1){
                y1=data[j][0];
                y2=data[j][1];
                countY1++;
                countY2++;
                continue;
            }
            if(data[j][0]==y1||data[j][1]==y1){
                countY1++;
            }
            if(data[j][0]==y2||data[j][1]==y2){
                countY2++;
            }
        }
        if(countX+countY1==data.length||countX+countY2==data.length){

            return true;
        }
        return false;
    }

}
