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 flagx = true, flagy = true;
        int? x = null, y = null;
        for(int a0 = 0; a0 < n; a0++){
            string[] tokens = Console.ReadLine().Split(' ');
            int x1 = Convert.ToInt32(tokens[0]);
            int y1 = Convert.ToInt32(tokens[1]);
            if(x==null)
                x=x1;
            if(y==null)
                y=y1;
            if(flagx && x!=x1)
                flagx = false;
            if(flagy && y!=y1)
                flagy = false;
        }
        if(flagx || flagy)
            Console.WriteLine("YES");
        else
            Console.WriteLine("NO");
    }
}