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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.StringTokenizer;

public class Pairs {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		MyScanner input =new MyScanner();
		int n = input.nextInt();
		int m = input.nextInt();
		//int[][] arr =new int[m][n+1];
		//int[][] arr =new int[m][n+1];
		int[][] arr = new int[m][2];
	//	HashSet<Integer> set =new HashSet<Integer>();
		for(int i=0; i<m;i++) {
		  arr[i][0] = input.nextInt();
		  arr[i][1] = input.nextInt();
	  //    set.add(arr[i][0]);
	//      set.add(arr[i][1]);
		}
		int x = arr[0][0];
		boolean condition = false;
		for(int i=1; i<m;i++) {
			if(arr[i][0]!=x && arr[i][1]!=x) {
				condition = true;
				int y = arr[i][0];
				if(check(x,y,arr,i+1)) {
					//System.out.println(x+"f"+y);
					System.out.println("YES");
					return;
				}
				else 
					break;
		
				
			//	y = arr[i][1];
			}
		}
		if(!condition) {
			System.out.println("YES");
			return;
		}
		condition =false;
		for(int i=1; i<m;i++) {
			if(arr[i][0]!=x && arr[i][1]!=x) {
			    condition = true;
				int  y =arr[i][1];
			   // System.out.println(x+" "+y+" "+i);
			     if(check(x,y,arr,i+1)) {
			//    	 System.out.println(x+"s"+y);
			    	 System.out.println("YES");
			    	 return;
			     }
			     else
			    	 break;
				
			}
	    }
		if(!condition) {
			System.out.println("YES");
			return;
		}
		condition =false;
		x = arr[0][1];
		for(int i=1; i<m;i++) {
			if(arr[i][0]!=x && arr[i][1]!=x) {
				condition = true;
				int y = arr[i][0];
				if(check(x,y,arr,i+1)) {
				//	System.out.println(x+"f"+y);
					System.out.println("YES");
					return;
				}
				else
					break;
			}
		}
		if(!condition) {
			System.out.println("YES");
			return;
		}
		for(int i=1; i<m;i++) {
			if(arr[i][0]!=x && arr[i][1]!=x) {
			    int  y =arr[i][1];
			     if(check(x,y,arr,i+1)) {
			    	 //System.out.println(x+"s"+y);
			    	 System.out.println("YES");
			    	 return;
			     }
			     else
			    	 break;
				
			}
	    }
		
		
	
		//System.out.println(check(2,4,arr,2));
		System.out.println("NO");
		

		
	}
	
	static boolean check(int x , int y, int[][] arr, int j) {
		for(int i=j;i<arr.length;i++) {
			if(arr[i][0]!=x && arr[i][1]!=x && arr[i][0]!=y && arr[i][1]!=y)return false;
		}
		return true;
	}
	
	

	static class MyScanner {
		BufferedReader br;
		StringTokenizer st;
		public MyScanner() {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;}
	}

}
