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.io.*;

public class two {

	public static void main(String[] args) throws IOException, FileNotFoundException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//BufferedReader in = new BufferedReader(new FileReader("two"));

		StringTokenizer st = new StringTokenizer(in.readLine());
		int n = Integer.parseInt(st.nextToken());
		int m = Integer.parseInt(st.nextToken());
		int[][] arr = new int[m][2];
		for (int i=0; i<m; i++ ) {
			st = new StringTokenizer(in.readLine());
			arr[i][0] = Integer.parseInt(st.nextToken());
			arr[i][1] = Integer.parseInt(st.nextToken());
		}
		
		int x = arr[0][0];
		int needed=0;
		HashMap<Integer, Integer> first= new HashMap<>();
		for (int i=1; i<m; i++) {
			if (arr[i][0] == x || arr[i][1] == x) {
				
			}
			else {
				first.put(arr[i][0], first.getOrDefault(arr[i][0], 0)+1);
				first.put(arr[i][1], first.getOrDefault(arr[i][1], 0)+1);
				needed++;
			}
		}
		
		if (first.size() == 0) {
			System.out.println("YES");
			return;
		}
		for (Integer z : first.keySet()) {
			if (first.get(z) >= needed) {
				System.out.println("YES");
				return;
			}
		}
		
		x = arr[0][1];
		needed=0;
		first= new HashMap<>();
		for (int i=1; i<m; i++) {
			if (arr[i][0] == x || arr[i][1] == x) {
				
			}
			else {
				first.put(arr[i][0], first.getOrDefault(arr[i][0], 0)+1);
				first.put(arr[i][1], first.getOrDefault(arr[i][1], 0)+1);
				needed++;
			}
		}
		
		if (first.size() == 0) {
			System.out.println("YES");
			return;
		}
		for (Integer z : first.keySet()) {
			if (first.get(z) >= needed) {
				System.out.println("YES");
				return;
			}
		}
		
		System.out.println("NO");
	}
}
