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.InputStreamReader;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.StringTokenizer;

public class B3 {
    public static void main(String args[]) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        int n = Integer.valueOf(st.nextToken());
        int m = Integer.valueOf(st.nextToken());
        ArrayList<int[]> pairs = new ArrayList<>();
        HashSet<String> set = new HashSet<>();
        for (int i = 0; i < m; i++) {
            st = new StringTokenizer(br.readLine());
            int x = Integer.valueOf(st.nextToken());
            int y = Integer.valueOf(st.nextToken());

            int[] pair  = {x, y};
            pairs.add(pair);
        }
        int[] first = pairs.get(0);
        for (int i = 0; i < 2; i++) {
            int a = first[i];
            int[] second = null;
            for (int j = 0; j < pairs.size(); j++) {
                int x = pairs.get(j)[0];
                int y = pairs.get(j)[1];
                if (!(a == x || a == y)) {
                    second = pairs.get(j);
                    break;
                }
            }
            if (second == null) {
                System.out.println("YES");
                return;
            }
            for (int j = 0; j < 2; j++) {
                int b = second[j];
                boolean works = true;
                for (int k = 0; k < pairs.size(); k++) {
                    int x = pairs.get(k)[0];
                    int y = pairs.get(k)[1];
                    if (!(a == x || a == y || b == x || b == y)) {
                        works = false;
                        break;
                    }
                }
                if (works) {
                    System.out.println("YES");
                    return;
                }
            }
        }
        System.out.println("NO");
    }
}
