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.io.PrintWriter;
import java.util.StringTokenizer;

public class B1169 {
    static BufferedReader br;
    static StringTokenizer st;
    static PrintWriter pw;

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

    static int nextInt() {
        return Integer.parseInt(nextToken());
    }

    static long nextLong() {
        return Long.parseLong(nextToken());
    }

    static String nextLine() throws IOException {
        return br.readLine();
    }

    static char nextChar() throws IOException {
        return (char) br.read();
    }

    public static void main(String[] args) {
        br = new BufferedReader(new InputStreamReader(System.in));
        pw = new PrintWriter(System.out);
        run();
        pw.close();
    }

    private static void run() {
        int n = nextInt();
        int m = nextInt();
        Pair a[] = new Pair[m];
        for (int i = 0; i < m; i++) {
            a[i] = new Pair(nextInt(), nextInt());
        }
        int y = -1;
        for (int i = 0; i < 2; i++) {
            int x = a[0].x[i];

            for (int j = 1; j < m; j++) {
                if (a[j].x[0] != x && a[j].x[1] != x) {
                    for (int k = 0; k < 2; k++) {
                        y = a[j].x[k];
                        boolean ans = true;
                        for (int l = j; l < m; l++) {
                            if (a[l].x[0] != x && a[l].x[1] != x && a[l].x[0] != y && a[l].x[1] != y) {
                                ans = false;
                                break;
                            }
                        }
                        if (ans) {
                            pw.print("YES");
                            return;
                        }
                    }
                    break;
                }
            }
        }
        if (y == -1) {
            pw.print("YES");
        } else
            pw.print("NO");
    }

    private static class Pair {
        int x[] = new int[2];

        public Pair(int x, int y) {
            this.x[0] = x;
            this.x[1] = y;
        }
    }
}
