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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
import java.util.ArrayList;


public class Main {
	
	static StreamTokenizer st=new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
	public static void main(String[] args) {
		int n=nextInt();
		int m=nextInt();
		int arr[][]=new int[m][2];	
		for(int i=0;i<m;i++){
			arr[i][0]=nextInt();
			arr[i][1]=nextInt();							
		}		
		int cnt=0;//
		int a=arr[0][0];
		while(cnt<2){
			ArrayList<Integer> list=new ArrayList<>();
			for(int i=0;i<m;i++){
				if(a!=arr[i][0]&&a!=arr[i][1])
					list.add(i);
			}
			if(list.size()>0){
				int b=arr[list.get(0)][0];
				boolean flag=true;
				for(int i=0;i<list.size();i++){
					if(b!=arr[list.get(i)][0]&&b!=arr[list.get(i)][1]){
						flag=false;
						break;
					}
				}
				if(flag){
					System.out.println("YES");
					return;
				}
				b=arr[list.get(0)][1];
				flag=true;
				for(int i=0;i<list.size();i++){
					if(b!=arr[list.get(i)][0]&&b!=arr[list.get(i)][1]){
						flag=false;
						break;
					}
				}
				if(flag){
					System.out.println("YES");
					return;
				}
			}else{
				System.out.println("YES");
				return;
			}
			a=arr[0][1];
			cnt++;
		}
		System.out.println("NO");
	}
	static int nextInt(){
		try {
			st.nextToken();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return (int)st.nval;
	}
}
