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());

        string[] tokens_x = Console.ReadLine().Split(' ');
        int x = Convert.ToInt32(tokens_x[0]);
        int y = Convert.ToInt32(tokens_x[1]);

        int x0 = x;
        int y0 = y;
        bool xLine = true;
        bool yLine = true;

        for (int a0 = 0; a0 < n -1; a0++) {
            tokens_x = Console.ReadLine().Split(' ');
            x = Convert.ToInt32(tokens_x[0]);
            y = Convert.ToInt32(tokens_x[1]);
            if (x0 != x) {
                xLine = false;
            }
            if (y0 != y) {
                yLine = false;
            }

        }
        string ans = xLine || yLine ? "YES" : "NO";
        Console.WriteLine(ans);


    }
}