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.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Scanner;
import java.util.StringTokenizer;

public class vk18
{

    public static void main(String[]stp) throws Exception {
        Scanner scan = new Scanner(System.in);
        PrintWriter pw = new PrintWriter(System.out);
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        int n = Integer.parseInt(st.nextToken()), m = Integer.parseInt(st.nextToken()),i;
        Integer a[]=new Integer[n+1];
        Integer b[]=new Integer[n+1];
        Arrays.fill(a,0);
        Arrays.fill(b,0);
        st=new StringTokenizer(br.readLine());
        int first=Integer.parseInt(st.nextToken()),second=Integer.parseInt(st.nextToken());
        int count1=0,count2=0;
        for(i=1;i<m;i++)
        {
        	st=new StringTokenizer(br.readLine());
            int p=Integer.parseInt(st.nextToken()),q=Integer.parseInt(st.nextToken());
            if(p!=first && q!=first)
            {
                a[p]++; a[q]++; count1++;
            }
            if(p!=second && q!=second)
            {
                b[p]++; b[q]++; count2++;
            }
        }
        boolean flag=false;
        for(i=0;i<n+1;i++)
        {
            if(a[i]==count1 || b[i]==count2) { pw.println("YES"); flag=true; break;}
        }
        if(!flag) pw.println("NO");
        pw.flush();
    }
}
