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.*;

public class Main {
  private static final boolean OJ = true;

  public static void main(String[] args) {
    try (BufferedReader reader = OJ ? new BufferedReader( new InputStreamReader(System.in)) : new BufferedReader(new FileReader("input"));
         Writer writer = OJ ? new OutputStreamWriter(System.out) : new FileWriter("output");
         PrintWriter out = new PrintWriter(writer);) {
      String line = null;
MAIN: while ((line = reader.readLine()) != null) {
        if (line.isEmpty()) {
          continue;
        }
        StringTokenizer tokenizer = new StringTokenizer(line);
        int n = Integer.parseInt(tokenizer.nextToken());
        int m = Integer.parseInt(tokenizer.nextToken());

        int[] x = new int[m];
        int[] y = new int[m];

        for (int t = 0; t < m; ++t) {
          tokenizer = new StringTokenizer(reader.readLine());
          int a = Integer.parseInt(tokenizer.nextToken());
          int b = Integer.parseInt(tokenizer.nextToken());
          if (a > b) {
            int tmp = a;
            a = b;
            b = tmp;
          }
          x[t] = a;
          y[t] = b;
        }
        for (int t = 1; t < m;++t) {
          if (x[t] == x[0] && y[t]==y[0]) continue;
          if (x[t] != x[0] && y[t] != y[0] && x[t] != y[0] && y[t] != x[0]) {
            if (checkXY(x[0], y[t], x, y, m)) {
              out.println("YES");
            } else if (checkXY(x[0], x[t], x, y, m)) {
              out.println("YES");
            } else if (checkXY(y[0], x[t], x, y, m)) {
              out.println("YES");
            } else if (checkXY(y[0], y[t], x, y, m)) {
              out.println("YES");
            } else out.println("NO");
            continue MAIN;
          } else if (x[t] == x[0]) {
            if (checkX(x[0], x, y, m)) {
              out.println("YES");
            } else if (checkXY(y[0], y[t], x, y, m)) {
              out.println("YES");
            } else out.println("NO");
            continue MAIN;
          } else if (x[t] == y[0]) {
            if (checkX(y[0], x, y, m)) {
              out.println("YES");
            } else if (checkXY(x[0], y[t], x, y, m)) {
              out.println("YES");
            } else out.println("NO");
            continue MAIN;
          } else if (y[t] == x[0]) {
            if (checkX(y[t], x, y, m)) {
              out.println("YES");
            } else if (checkXY(y[0], x[t], x, y, m)) {
              out.println("YES");
            } else out.println("NO");
            continue MAIN;
          } else if (y[t] == y[0]) {
            if (checkX(y[0], x, y, m)) {
              out.println("YES");
            } else if (checkXY(x[0], x[t], x, y, m)) {
              out.println("YES");
            } else out.println("NO");
            continue MAIN;
          }
        }
        out.println("YES");
      }
    } catch (Exception e) {
      e.printStackTrace(System.err);
    }
  }

  static boolean checkX(int ansx, int[] x, int[] y, int m) {
    for (int i = 1; i < m; ++i) {
      if (x[i] != ansx && y[i] != ansx) {
        return checkXY(ansx, x[i], x, y, m) || checkXY(ansx, y[i], x, y, m);
      }
    }
    return true;
  }
  static boolean checkXY(int ansx, int ansy, int[] x, int[] y, int m) {
    for (int s = 1; s < m; ++s) {
      if (x[s] != ansx && x[s] != ansy && y[s] != ansx && y[s] != ansy) {
        return false;
      }
    }
    return true;
  }

  static void debug(String s) {
    System.out.println(s);
  }
}
