using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    static void Main(String[] args) {
        int mainX=0,mainY=0;
        bool statusX=true,statusY=true;
        int n = Convert.ToInt32(Console.ReadLine());
        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 (a0==0)
                {
                mainX=x;
                mainY=y;
            }
            else{
                
                if ( x!=mainX)
                    statusX=false;
                if(y!=mainY)
                    statusY=false;
                if((x!=mainX&&y!=mainY))
                {
                    
                    break;
                } 
            }
            
        }
        if (statusX||statusY)
            Console.WriteLine("YES");
        else
            Console.WriteLine("NO");
    }
}