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.
//package com.pb.codeforces.practice;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.StringTokenizer;

public class CF1169B {
	public static class FastReader {
		BufferedReader br;
		StringTokenizer st;

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

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

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

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

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

		public String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}
	
	public static boolean solve(HashMap<Integer,HashMap<Integer,Integer>> adj, int x, int m) {
		int rem = m;
		for(int k : adj.get(x).keySet()) {
			rem -= adj.get(x).get(k);
		}
		for(int k : adj.keySet()) {
			if(k == x) continue;
			int sum = 0;
			for(int kk : adj.get(k).keySet()) {
				if(kk == x) continue;
				sum += adj.get(k).get(kk);
			}
			if(sum >= rem) return true;
		}
		return false;
	}
	
	public static void main(String[] args) {
		FastReader in = new FastReader();
		PrintWriter out = new PrintWriter(System.out);
		int n = in.nextInt(); int m = in.nextInt();
		HashMap<Integer,HashMap<Integer,Integer>> adj = new HashMap<Integer,HashMap<Integer,Integer>>();
		int a,b;
		a = b = 0;
		for(int i=0; i<m; i++) {
			a = in.nextInt(); b = in.nextInt();
			if(!adj.containsKey(a))
				adj.put(a, new HashMap<Integer,Integer>());
			if(!adj.containsKey(b))
				adj.put(b, new HashMap<Integer,Integer>());
			adj.get(a).put(b, adj.get(a).getOrDefault(b, 0)+1);
			adj.get(b).put(a, adj.get(b).getOrDefault(a, 0)+1);
		}
		boolean possible = false;
		possible = possible || solve(adj,a,m);
		possible = possible || solve(adj,b,m);
		if(possible)
			out.println("YES");
		else
			out.println("NO");
		out.flush();
		out.close();
			
	}
}
