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());
        int[] x = new int[n];
        int[] y = new int[n];
        for(int a0 = 0; a0 < n; a0++){
            string[] tokens_x = Console.ReadLine().Split(' ');
            x[a0] = Convert.ToInt32(tokens_x[0]);
            y[a0] = Convert.ToInt32(tokens_x[1]);
        }
        var x1 = x[0];
        var y1 = y[0];
        if(x.All(it => it == x1) || y.All(it => it == y1)) {
            Console.WriteLine("YES");
        }else Console.WriteLine("NO");
    }
}