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.*;
import java.util.*;

public class cf {
    static class FastScanner {
        BufferedReader br;
        StringTokenizer st;
        
        public FastScanner(Reader in) {
            br = new BufferedReader(in);
        }
        
        public FastScanner() {
            this(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;
        }
        
        int[] nextIntArray(int n) {
            int[] a = new int[n];
            for (int idx = 0; idx < n; idx++) {
                a[idx] = nextInt();
            }
            return a;
        }
    }

    static int mod = 1000000007;
    
	public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter pw = new PrintWriter(System.out); 

        int n = sc.nextInt(), m = sc.nextInt();
       
        int[] a1 = new int[m];
        int[] a2 = new int[m];

        for(int i=0;i<m;i++) {
            a1[i] = sc.nextInt();
            a2[i] = sc.nextInt();
        }

        boolean ans = check(a1, a2, a1[0]) || check(a1, a2, a2[0]);
        pw.println(ans ? "Yes" : "No");
        pw.close();   
    }

    public static boolean check(int[] arr1, int[] arr2, int k) {
        HashSet<Integer> set = new HashSet<>();
        for(int i=0;i<arr1.length;i++) {
            if(arr1[i] != k && arr2[i] != k) {
                int c = arr1[i];
                int d = arr2[i];
                if(set.size() == 0) {
                    set.add(c);
                    set.add(d);
                }
                else {
                    HashSet<Integer> temp = new HashSet<>();
                    temp.add(c);
                    temp.add(d);
                    set.retainAll(temp);
                    if(set.size() == 0) {
                        return false;
                    }
                }
            }
        }
        return true;
    }
}
