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[] ax = new int[n];
        int[] ay = new int[n];
        int countx = 0;
        int county = 0;
        for(int a0 = 0; a0 < n; a0++){
            int x = in.nextInt();
            int y = in.nextInt();
            ax[a0] = x;
            ay[a0] = y;
        }
        
            for(int a = 1; a < n; a++)
                {
                if (ax[0] == ax[a])
                    {
                    
                    }
                else{countx += 1;}
                
                if (ay[0] == ay[a])
                    {
                    
                    }
                else{county+= 1;}
            
            }
        if (county == 0 || countx == 0)
                {System.out.println("YES");}
            else {System.out.println("NO");}
                
    }
        }