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 CF_1110 {
      
    public static void main(String[] args) throws IOException{
        FastReader scn = new FastReader() ;
        int n = scn.nextInt() , m = scn.nextInt() ;
        Vector<Pair> v = new Vector<>() ;
        for(int i = 0 ; i < m ; i++){
            int x = scn.nextInt() , y = scn.nextInt() ;
            v.add(new Pair(x , y)) ;
        }
        int[] lp = new int[]{v.get(0).f , v.get(0).s} ;
        for(int x : lp){
            int all = 0 ;
            Integer[] val = new Integer[n + 1] ;
            Arrays.fill(val , 0) ;
            for(Pair p : v){
                if(p.f != x && p.s != x){
                    val[p.f]  = val[p.f] + 1;
                    val[p.s]= val[p.s ] + 1 ;
                    all++ ;
                }
            }
            Arrays.sort(val , Comparator.reverseOrder()) ;
            if(val[0] == all){
                System.out.println("YES");
                return ;
            }
            
        }
        System.out.println("NO");

     }
     
    
     static class Pair {
        int f ; 
        int s ;
        Pair(int f , int s){
            this.f = f ; 
            this.s = s ;
        }
    }
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
     
 }