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.Arrays;
import java.util.Scanner;

public class Main{
	static int a[]=new int[310000];
	static int b[]=new int[310000];
	static int n,m;
	static int f(int x) {
		int c[]=new int[310000];
		int cnt=0;
		for(int i=1;i<=m;i++) {
			if(a[i]!=x&&b[i]!=x) {
				c[a[i]]++;
				c[b[i]]++;
				cnt++;
			}
		}Arrays.sort(c,1,n+1);
		if(c[n]==cnt)
			return 1;
		else
			return 0;
		
	}
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()) {
			 n=sc.nextInt();
			 m=sc.nextInt();
			for(int i=1;i<=m;i++) {
				a[i]=sc.nextInt();
				b[i]=sc.nextInt();
			}
			if(f(a[1])==1||f(b[1])==1) {
				System.out.println("YES");
			}
			else {
				System.out.println("NO");
			}
		}
	}
}