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 mymy
{

	static OutputStream outputStream = System.out;
	static PrintWriter out = new PrintWriter(outputStream);	

	static class node implements Comparable<node>
	{
		int data;int indx;

		node(int i,int o)
		{
			data=i;indx=o;
		}
		public int compareTo(node n)
		{
			if(this.data!=n.data) return this.data-n.data;
			return this.indx-n.indx;
		}
	}
	


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

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

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

		node[] a=new node[m];

		for(int i=0;i<m;i++)
		{
			s=br.readLine().split(" ");
			a[i]=new node(Integer.parseInt(s[0]),Integer.parseInt(s[1]));
		}

		int num1=a[0].data,num2=a[0].indx,num3=-1,num4=-1;


		for(int i=1;i<m;i++)
		{
			if(a[i].data!=num1 && a[i].data!=num2 && a[i].indx!=num1 && a[i].indx!=num2)
			{
				num3=a[i].data;num4=a[i].indx;
				break;
			}
		}

		if(num3==-1)
		{
			out.println("YES");
			out.close();
			System.exit(0);
		}

		int flg=0;

		int c=0;

		c=0;
		for(int i=0;i<m;i++)
		{
			if((a[i].data==num1 || a[i].data==num3)||(a[i].indx==num1 || a[i].indx==num3)) c++;
		}

		if(c==m) flg=1;


		c=0;
		for(int i=0;i<m;i++)
		{
			if((a[i].data==num1 || a[i].data==num4)||(a[i].indx==num1 || a[i].indx==num4)) c++;
		}

		if(c==m) flg=1;


		c=0;
		for(int i=0;i<m;i++)
		{
			if((a[i].data==num2 || a[i].data==num3)||(a[i].indx==num2 || a[i].indx==num3)) c++;
		}

		if(c==m) flg=1;


		c=0;
		for(int i=0;i<m;i++)
		{
			if((a[i].data==num2 || a[i].data==num4)||(a[i].indx==num2 || a[i].indx==num4)) c++;
		}

		if(c==m) flg=1;


		if(flg==1) out.println("YES");
		else out.println("NO");


		
		out.close();

	}
}