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.
//Author: Patel Rag
import java.util.*;
import java.io.*;
//import javafx.util.*;

public class Main
{

  static class FastReader
  {
    BufferedReader br;
    StringTokenizer st;

    public FastReader(){ br = new BufferedReader(new InputStreamReader(System.in)); }

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

    int nextInt() { return Integer.parseInt(next()); }

    long nextLong(){ return Long.parseLong(next()); }

    double nextDouble(){ return Double.parseDouble(next()); }

    float nextFloat() { return Float.parseFloat(next()); }

    boolean nextBoolean() { return Boolean.parseBoolean(next()); }

    String nextLine()
    {
      String str = "";
      try
      {
        str = br.readLine();
      }
      catch (IOException e)
      {
        e.printStackTrace();
      }
      return str;
    }
  }

  public static void main(String[] args)
  throws IOException
  {
    FastReader fr = new FastReader();
    int n = fr.nextInt();
    int m = fr.nextInt();

    int[][] dat = new int[m][2];
    for(int i = 0; i < m; i++)
    {
      dat[i][0] = fr.nextInt();
      dat[i][1] = fr.nextInt();
    }
    for(int i = 0; i < 2; i++)
    {
      int x = dat[0][i];
      int[] count = new int[n+1];
      Arrays.fill(count,0);
      int tot = 0;
      for(int j = 0; j < m; j++)
      {
        if(dat[j][0] != x && dat[j][1] != x)
        {
          count[dat[j][0]]++; count[dat[j][1]]++;
          tot++;
        }
      }
      Arrays.sort(count);
      if(count[n] == tot)
      {
        System.out.println("YES");
        return;
      }
    }
    System.out.println("NO");

  }
}
