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());
        List<int> xs = new List<int>();
        List<int> ys = new List<int>();
        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]);
            xs.Add(x);
            ys.Add(y);
        }
        var ans= (xs.Distinct().Skip(1).Any() && ys.Distinct().Skip(1).Any())? "NO":"YES";
        Console.WriteLine(ans);
    }
}