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 horizontal = true;        
        bool vertical = true;
        int h = 0;
        int v = 0;
        for(int a0 = 0; a0 < n; a0++){
            string[] tokens_x = Console.ReadLine().Split(' ');
            int x = Convert.ToInt32(tokens_x[0]);            
            if(a0 == 0)
                h = x;
            else
                if(h != x)
                    horizontal = false;
            int y = Convert.ToInt32(tokens_x[1]);
            if(a0 == 0)
                v = y;
            else
                if(v != y)
                    vertical = false;
        }
        if(horizontal || vertical)
            Console.WriteLine("YES");
        else
            Console.WriteLine("NO");
    }
}