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.
/*
lmao
*/
import java.util.*;
import java.io.*;

   public class B
   {
      public static void main(String args[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));  
         StringTokenizer st = new StringTokenizer(infile.readLine());
         int N = Integer.parseInt(st.nextToken());
         int M = Integer.parseInt(st.nextToken());
         int[] a1 = new int[M];
         int[] a2 = new int[M];
         for(int i=0; i < M; i++)
         {
            st = new StringTokenizer(infile.readLine());
            int x = Integer.parseInt(st.nextToken());
            int y = Integer.parseInt(st.nextToken());
            a1[i] = x;
            a2[i] = y;
         }
         //why am I so small brain
         boolean res = check(a1, a2, a1[0]) || check(a1, a2, a2[0]);
         if(res)
            System.out.println("YES");
         else
            System.out.println("NO");
      }
      public static boolean check(int[] arr1, int[] arr2, int x)
      {
         HashSet<Integer> set = new HashSet<Integer>();
         for(int i=0; i < arr1.length; i++)
         {
            if(arr1[i] != x && arr2[i] != x)
            {
               int c = arr1[i];
               int d = arr2[i];
               if(set.size() == 0)
               {
                  set.add(c);
                  set.add(d);
               }
               else
               {
                  HashSet<Integer> temp = new HashSet<Integer>();
                  temp.add(c);
                  temp.add(d);
                  set.retainAll(temp);
                  if(set.size() == 0)
                     return false;
               }
            }
         }
         return true;
      }
   }