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.*;
import javafx.util.Pair;

public class codef
{
	public static void main(String args[])throws Exception
	{
	BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

	String str[]=br.readLine().split(" ");

	int m=Integer.parseInt(str[0]);
	int n=Integer.parseInt(str[1]);

	Pair<Integer,Integer> p[]=new Pair[n];

	for(int i=0;i<n;i++)
	{
		String xx[]=br.readLine().split(" ");
		p[i]=new Pair(Integer.parseInt(xx[0]),Integer.parseInt(xx[1]));
	}

	ArrayList<Integer>ar=new ArrayList<Integer>();


	int x=p[0].getKey();


	int cnt=0;

	for(int i=1;i<n;i++)
	{
		if((p[i].getKey()!=x)&&(p[i].getValue()!=x))
		{
			cnt++;

			ar.add(i);

		}
	}

	HashMap<Integer,Integer>hm=new HashMap<>();

	for( int z : ar)
	{
		if(hm.containsKey(p[z].getKey()))
		{
			int aa=hm.get(p[z].getKey());
			if((aa+1)==cnt)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getKey(),aa+1);
		}

		else
		{

			if(cnt==1)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getKey(),1);
		}


		if(hm.containsKey(p[z].getValue()))
		{
			int aa=hm.get(p[z].getValue());
			if((aa+1)==cnt)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getValue(),aa+1);
		}

		else
		{

			if(cnt==1)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getValue(),1);
		}


	}


	hm.clear();

ar.clear();














	int y=p[0].getValue();

	


	 int cnt1=0;

	for(int i=1;i<n;i++)
	{
		if((p[i].getKey()!=y)&&(p[i].getValue()!=y))
		{
			cnt1++;

			ar.add(i);

		}
	}

	

	if((cnt==0)&&(cnt1==0))
	{
		System.out.println("YES");
		return;
	}


	
	for( int z : ar)
	{
		if(hm.containsKey(p[z].getKey()))
		{
			int aa=hm.get(p[z].getKey());
			if((aa+1)==cnt1)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getKey(),aa+1);
		}

		else
		{
			if(cnt1==1)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getKey(),1);
		}


		if(hm.containsKey(p[z].getValue()))
		{
			int aa=hm.get(p[z].getValue());
						
			if((aa+1)==cnt1)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getValue(),aa+1);
		}

		else
		{

			if(cnt1==1)
			{
				System.out.println("YES");
				return;
			}
			hm.put(p[z].getValue(),1);
		}


	}


	System.out.println("NO");




	


	
	
	}
}