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

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int x[]=new int[20];
        int y[]=new int[20];
        int i;
        for(i = 0; i < n; i++){
            x[i] = in.nextInt();
            y[i] = in.nextInt();
        }
        
        int z=0;
        int q=0;
        for(i=0;i<n;i++)
        {
            if(x[i]!=x[0]) z=1;
        }
        
        for(i=0;i<n;i++)
        {
            if(y[i]!=y[0]) q=1;
        }
        
        if(z==0 || q==0) 
            System.out.println("YES");
        else 
            System.out.println("NO");
    }
}