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.*;
import java.util.ArrayList;
import java.util.List;

public class Solution {

    static class Pair {
        int first;
        int second;

        Pair(int first, int second) {
            this.first = first;
            this.second = second;
        }
    }

    private static final BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    private static final BufferedWriter out = new BufferedWriter(new OutputStreamWriter(System.out));


    public static void main(String[] args) throws IOException {
        String[] mn = in.readLine().split(" ");
        int n = Integer.parseInt(mn[0]);
        int m = Integer.parseInt(mn[1]);
        List<Pair> pairs = new ArrayList<>(m);
        while (m-- > 0) {
            String[] ab = in.readLine().split(" ");
            pairs.add(new Pair(
                    Integer.parseInt(ab[0]), Integer.parseInt(ab[1])
            ));
        }
        solve(pairs);
        out.flush();
    }

    private static void solve(List<Pair> pairs) throws IOException {
        int[] xs = {pairs.get(0).first, pairs.get(0).second};
        for (int x : xs) {
            if (cover(x, -1, pairs)) {
                out.write("YES");
                out.newLine();
                return;
            }
            for (int i = 1; i < pairs.size(); ++i) {
                Pair p = pairs.get(i);
                if (x != p.first && x != p.second) {
                    if (cover(x, p.first, pairs) || cover(x, p.second, pairs)) {
                        out.write("YES");
                        out.newLine();
                        return;
                    }
                    break;
                }
            }
        }
        out.write("NO");
        out.newLine();
    }

    private static boolean cover(int x, int y, List<Pair> pairs) {
        for (Pair p : pairs) {
            if (x != p.first && x != p.second && y != p.first && y != p.second) {
                return false;
            }
        }
        return true;
    }
}