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.util.*;
import java.io.*;
public class b{
    static boolean find(int [][] a,int ind,int n){
        int [] map=new int[n+1];
        Arrays.fill(map,0);
        int x=a[0][ind];
        int cnt=1;

        for(int i=1;i<a.length;i++){
            if(a[i][0]==x || a[i][1]==x){
                cnt++;
            }
            else{
                map[a[i][0]]++;map[a[i][1]]++;
            }
        }

        int max=-1;
        for(int i : map){
            max=Math.max(i,max);
        }
        return (cnt+max)>=a.length;
    }
       public static void main(final String [] args)throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        String [] data=br.readLine().trim().split(" ");
        int n=Integer.parseInt(data[0]);
        int m=Integer.parseInt(data[1]);
        int [][] a=new int[m][2];
        for(int i=0;i<m;i++){
            data=br.readLine().trim().split(" ");
            a[i][0]=Integer.parseInt(data[0]);
            a[i][1]=Integer.parseInt(data[1]);
        }
        if(find(a, 0, n)||find(a,1,n)){
            System.out.println("YES");
        }
        else{
            System.out.println("NO");
        }

    }
}