import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    
	public static String solution(int[] arrx,int[] arry)
	{
		int flagx=0;
		int flagy=0;
		
		for(int i=1;i<arrx.length;i++)
		{
			if(arrx[i-1]!=arrx[i])
			{
				flagx=1;
				break;
			}
		}
		for(int i=1;i<arry.length;i++)
		{
			if(arry[i-1]!=arry[i])
			{
				flagy=1;
				break;
			}
		}
		
		if(flagx==1&&flagy==1){
		return "NO";
		}
		else
		{
			return "YES";
		}
		
	}
	
	
	 public static void main(String[] args) 
	 {
	        Scanner in = new Scanner(System.in);
	        int n = in.nextInt();
	        int[] arrx=new int[n];
	        int[] arry=new int[n];
	        for(int a0 = 0; a0 < n; a0++){
	            int x = in.nextInt();
	            int y = in.nextInt();
	            arrx[a0]=x;
	            arry[a0]=y;
	        }
	        System.out.println(solution(arrx,arry));
	    }

}