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.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.StringTokenizer;

public class mai {

	static class FastReader {
		BufferedReader br;
		StringTokenizer st;

		public FastReader() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String next() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		int nextInt() {
			return Integer.parseInt(next());
		}

		long nextLong() {
			return Long.parseLong(next());
		}

		double nextDouble() {
			return Double.parseDouble(next());
		}

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}

	public static void main(String[] args) throws NumberFormatException, IOException {
		// TODO Auto-generated method stub

		FastReader sc = new FastReader();
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		Scanner scn = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
int arr[][]=new int[m][2];
//boolean dp[][]=new boolean[n+1][n+1];
for(int i=0;i<m;i++)
{
	arr[i][0]=sc.nextInt();
	arr[i][1]=sc.nextInt();
	
	}
int flag=0;
int i=0;
	while((i<m) && (arr[i][0]==arr[0][0] || arr[i][1]==arr[0][0]) )
	{
		i++;
		
	}
	int j=i;
	while((j<m) && (arr[i][0]==arr[j][0] || arr[i][0]==arr[j][1] || arr[0][0]==arr[j][0] || arr[0][0]==arr[j][1]) )
	{
		j++;
	}
	if(j==m)
	{
		System.out.println("YES"); 
		return;
	}
	 j=i;
	while((j<m) && (arr[i][1]==arr[j][0] || arr[i][1]==arr[j][1] || arr[0][0]==arr[j][0] || arr[0][0]==arr[j][1]) )
	{
		j++;
	}
	if(j==m)
	{
		System.out.println("YES"); 
	return;	
	}
	
	
	i=0;
	while((i<m) && (arr[i][0]==arr[0][1] || arr[i][1]==arr[0][1]) )
	{
		i++;
		
	}
	 j=i;
	while((j<m) && (arr[i][0]==arr[j][0] || arr[i][0]==arr[j][1] || arr[0][1]==arr[j][0] || arr[0][1]==arr[j][1]) )
	{
		j++;
	}
	if(j==m)
	{
		System.out.println("YES"); 
		return;
	}
	 j=i;
	while((j<m) && (arr[i][1]==arr[j][0] || arr[i][1]==arr[j][1] || arr[0][1]==arr[j][0] || arr[0][1]==arr[j][1]) )
	{
		j++;
	}
	if(j==m)
	{
		System.out.println("YES"); 
	return;	
	}
	
	System.out.println("NO");
	
	
	}
}