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.*;
public class q2{
    public static void main(String args[]){
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int m=sc.nextInt();
        int a[][]=new int[n][2];
        for(int i=0;i<n;i++){
            a[i][0]=i;
        }
        int b[][]=new int[m][2];
        for(int i=0;i<m;i++){
            int x=sc.nextInt();
            int y=sc.nextInt();
            a[x-1][1]++;
            a[y-1][1]++;
            b[i][0]=x-1;
            b[i][1]=y-1;
        }
        Arrays.sort(a,(a1,a2)->a2[1]-a1[1]);
        boolean v[]=new boolean[m];
        l1:for(int i=0;i<Math.min(n,4) &&a[i][1]>=Math.ceil(m/2.0);i++){
            //System.out.println(a[i][0]);
            for(int j=0;j<m;j++)
                if(a[i][0]==b[j][0]|| a[i][0]==b[j][1])v[j]=true;
            boolean flag=false;
            int x=-1,y=-1;
            for(int j=0;j<m;j++){
                if(!flag && !v[j]){
                    x=b[j][1];
                    y=b[j][0];
                    flag=true;
                }
                else if(flag && !v[j]){
                    if(x!=b[j][1]&& x!=b[j][0])x=-2;
                    if(y!=b[j][1]&& y!=b[j][0])y=-2;
                }
                if(x==-2 && y==-2){
                    //System.out.println("NO");
                    Arrays.fill(v,false);
                    continue l1;
                    
                    //System.exit(0);
                }
            }
            
            System.out.println("YES");
            System.exit(0);

        }
        System.out.println("NO");
    }
}