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());
        var xs = new int[n];
        var ys = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            string[] tokens_x = Console.ReadLine().Split(' ');
            xs[a0] = Convert.ToInt32(tokens_x[0]);
            ys[a0] = Convert.ToInt32(tokens_x[1]);            
        }
        
        var firstx = xs[0];
        var firsty = ys[0];
        var output = xs.All(x => x == firstx) || ys.All(y => y == firsty);
        Console.WriteLine(output? "YES" : "NO");
    }
}