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.*;
import java.math.*;
public class B562{
	
	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;
		}
	}

	static class pair{
		int first,second;
		pair(int f,int s){
			first=f;
			second=s;
		}
	}

	public static long fastexpo(long x, long y, long p){
		long res=1;
		while(y > 0){
			if((y & 1)==1)
				res= ((res%p)*(x%p))%p;
			y= y >> 1;			
			x = ((x%p)*(x%p))%p;
		}
		return res;
	}

	public static boolean[] sieve (int n) {
		boolean primes[]=new boolean[n+1];
		Arrays.fill(primes,true);
		primes[0]=primes[1]=false;
		for(int i=2;i*i<=n;i++){
			if(primes[i]){
				for(int j=i*i;j<=n;j+=i)
					primes[j]=false;
			}
		}
		return primes;
	}

	public static long gcd(long a,long b){
        return (BigInteger.valueOf(a).gcd(BigInteger.valueOf(b))).longValue();
    }
    public static boolean present(pair[] a,int n, int v){
    	int val[]=new int[n+1];
    	Arrays.fill(val,0);
    	int count=0;
    	for(pair x: a){
    		if(x.first==v||x.second==v)
    			continue;
    		else{
    			val[x.first]++;val[x.second]++;
    			count++;
    		}
    	}
    	for(int i=1;i<=n;i++){
    		if(val[i]==count)
    			return true;
    	}
    	return false;
    }
    
	
	public static void main(String args[]){
		FastReader sc = new FastReader();
		int n,m,i;
		boolean ans;
		n=sc.nextInt();
		m=sc.nextInt();
		pair a[]=new pair[m];
		for(i=0;i<m;i++)
			a[i]=new pair(sc.nextInt(),sc.nextInt());
		ans=false;
		ans=ans|present(a,n,a[0].first);
		ans=ans|present(a,n,a[0].second);
		if(ans)
			System.out.println("YES");
		else 
			System.out.println("NO");
	}
}


