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.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import javafx.util.Pair;

public class Pairs {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt(), m = sc.nextInt();
		List<Pair<Integer, Integer>> values = new ArrayList<Pair<Integer, Integer>>();
		while (m-- > 0) {
			values.add(new Pair<Integer, Integer>(sc.nextInt(), sc.nextInt()));
		}
		int arr_val[] = { values.get(0).getKey(), values.get(0).getValue() };

		
		sc.close();
		for (int val : arr_val) {
			int val_count[] = new int[n+1];
			int all = 0;
			for (Pair<Integer, Integer> pair : values) {
				if (pair.getKey() != val && pair.getValue() != val) {
					val_count[pair.getKey()]++;
					val_count[pair.getValue()]++;
					all++;
				}
			}
			int max = Arrays.stream(val_count).max().getAsInt();
			if (max == all) {
				System.out.println("YES\n");
				return;
			}
		}
		System.out.println("NO\n");
	}
}
