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.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
	 Scanner sc=new Scanner(System.in);
	 int n=sc.nextInt(),m=sc.nextInt();
	 
	 int[] a=new int[m];
	 int[] b=new int[m];
	 boolean flag=false;
	 
	 for(int i=0;i<m;i++){
	  a[i]=sc.nextInt();
	  b[i]=sc.nextInt();
	 }
	 int[] arr=new int[2];
	 arr[0]=a[0]; arr[1]=b[0];
	 
	 for(int i=0;i<2;i++){
	 	int all=0;
	 	int[] aux=new int[n+1];
	  for(int j=0;j<m;j++){
	  	if(arr[i]!=a[j] && arr[i]!=b[j]){
	  	 aux[a[j]]++;aux[b[j]]++;all++;	
	  	}
	  }
	  int max=0;
	 for(int k=0;k<=n;k++){
	  max=Math.max(max,aux[k]);	
	 }
	 if(max==all) {System.out.println("YES");flag=true;break;}
	 }
	 
	 if(!flag)
	 System.out.println("NO");
	}
}