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 isFirst = true;
        int allX = 0;
        int allY = 0;
        bool allXSame = true;
        bool allYSame = true;
        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]);
            if(isFirst){
                allX = x;
                allY = y;
                isFirst = false;
            }
            else{
                if(x!=allX) allXSame = false;
                if(y!=allY) allYSame = false;
            }
            
        }
        if(allXSame || allYSame) Console.WriteLine("YES"); else Console.WriteLine("NO");
    }
}