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.*;
public class May {
 
	static  long N = (long) (2e5 + 5);
	static  long MAX = (long) (2e3 + 5);
	static List<Pair> list = new ArrayList<>();
	static int ui, vi;

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		
		  int n, m;
		  n = sc.nextInt();
		  m = sc.nextInt();
		 
		    int t = m;
		    while(m-->0)
		    {
		        int a = sc.nextInt(), b = sc.nextInt();
		       Pair p = new Pair(a,b);
		       list.add(p);
		        
		    }
		    
		    boolean q1 = f(list.get(0).first, t);
		    boolean q2 = f(list.get(0).second, t);
		    
		    if(q1|| q2)
		    {
		        System.out.println("YES");
		    }
		    else
		    {
		        System.out.println("NO");
		    }
		    
		    
		}
	static boolean check(int v1, int v2, int m)
	{
	    int i = 0;
	    while(m-->0)
	    {
	        if(list.get(i).first == v1 || list.get(i).second == v1 || list.get(i).first == v2 || list.get(i).second == v2)
	        {
	            
	        }
	        else
	        {
	            return false;
	        }
	        i++;
	    }
	    
	    return true;
	    
	}

	
	

	static boolean f(int way, int m)
	{
	    int t = m;
	    int i = 0;
	    
	    while(t-->0)
	    {
	        if(list.get(i).first == way || list.get(i).second == way)
	        {
	            
	        }
	        else
	        {
	            boolean ok = check(way, list.get(i).first, m);
	            
	            if(ok)
	            {
	                ui = way;
	                vi = list.get(i).first;
	                return true;
	            }
	            
	            ok = check(way, list.get(i).second, m);
	            
	            if(ok)
	            {
	                ui = way;
	                vi = list.get(i).first;
	                return true;
	            }
	            
	            return false;
	            
	        }
	        
	        i++;
	        
	    }
	    
	    ui = way;
	    vi = way + 1;
	    return true;
	}
    


	static class Pair{
    	int first;
    	int second;
    	Pair(int first,int second){
    		this.first = first;
    		this.second = second;
    }
	//int[] arr = [N];
	
	}


}