using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    static void Main(String[] args) {
        int n = Convert.ToInt32(Console.ReadLine());
        int[] x=new int[n];
        int[] y=new int[n];
        int count_x=0, count_y=0;
        for(int a0 = 0; a0 < n; a0++){
            string[] tokens_x = Console.ReadLine().Split(' ');
            x[a0] = Convert.ToInt32(tokens_x[0]);
            y[a0] = Convert.ToInt32(tokens_x[1]);
        }
        int x1=x[0];
        int y1=y[0];
        for(int i=0;i<n;i++){
            if(x[i]==x1){
                count_x++;
            }
            if(y[i]==y1){
                count_y++;
            }
        }
        if(count_x == (n) || count_y == (n)){
            Console.WriteLine("YES");
        }
        else{
            Console.WriteLine("NO");
        }
    }
}