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.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    static class Reader {
        static BufferedReader reader;
        static StringTokenizer tokenizer;
        static void init(InputStream input) {
            reader = new BufferedReader(
                    new InputStreamReader(input));
            tokenizer = new StringTokenizer("");
        }
        static String next() throws IOException {
            while (!tokenizer.hasMoreTokens()) {
                tokenizer = new StringTokenizer(
                        reader.readLine());
            }
            return tokenizer.nextToken();
        }
        static int nextInt() throws IOException {
            return Integer.parseInt(next());
        }
    }
    public static void main(String[] args) throws java.lang.Exception {
        Reader.init(System.in);
        int n = Reader.nextInt();
        int m = Reader.nextInt();
        int[][] arr =  new int[m][2];
      //  int[] count = new int[n+1];
         int FLAG =0;
        for(int i=0;i<m;i++)
            for(int j=0;j<2;j++)
                arr[i][j] =  Reader.nextInt();
        for(int k=0;k<2;k++){
            int flag=0;
            int y = arr[0][k];
            for(int i=1;i<m;i++)
                if(arr[i][0]!=y&&arr[i][1]!=y){
                    flag =1;
                    for(int k2 = 0;k2<2;k2++){
                        int x = arr[i][k2];
                        int flag2 =1;
                        for(int j=1;j<m;j++)
                        {
                            if(arr[j][0]!=y && arr[j][0]!=x && arr[j][1] !=y && arr[j][1] != x)
                                flag2 =0;
                        }
                        if (FLAG==1)
                            FLAG = 1;
                        if (flag2==1)
                            FLAG = 1;
                    }
                    break;
                }
                if(flag==0)
                    FLAG =1;

        }
        if(FLAG==1)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}
