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 Pairs {
	static boolean done = false;
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		int m = scan.nextInt();
		int arr[][] = new int[m+1][2];
		for (int i = 0 ; i < m ; i++) {
			arr[i][0] = scan.nextInt();
			arr[i][1] = scan.nextInt();
		}
				
		check(arr[0][0], arr, n+1);
		if (done)
			return ;
		check(arr[0][1], arr, n+1);
		if (!done)
			System.out.println("NO");
}
	
	public static void check(int num, int[][] arr, int n) {
		int k = 1;
		int[] rep = new int[n];
		for (int i = 1 ; i < arr.length ; i++) {
			if (arr[i][0] != num && arr[i][1] != num) {
				rep[arr[i][0]]++;
				rep[arr[i][1]]++;
			} else {
				k++;
			}
		}
		for (int i = 0 ; i < n ; i++) {
			if (rep[i] == (arr.length - 1) - k) {
				System.out.println("YES");
				done = true;
				return ;
			}
		}
	}

}
