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());
        bool v=true, h=true;
        int x0=0, y0=0;
        for(int a0 = 0; a0 < n; a0++){
            string[] tokens_x = Console.ReadLine().Split(' ');
            int x = Convert.ToInt32(tokens_x[0]);
            int y = Convert.ToInt32(tokens_x[1]);
            
            if(a0==0){x0=x; y0=y;}
            else
                {
                    v&=x0==x;
                    h&=y0==y;
            }
        }
        
        if(v | h) Console.WriteLine("YES");
        else  Console.WriteLine("NO");
    }
}