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[] x0 =new int[n]; int[] y0=new int[n];
        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]);
            
           
           x0[a0] = x;
           y0[a0] = y;
            
        }
         int tempx = x0[0];
        int tempy = y0[0];
        int yesx = 0; int yesy =0;
        for(int i = 1; i <n; i++){
            if(x0[i]== tempx){
                yesx += 1;
            }
            if(y0[i]==tempy){
                yesy += 1;
            }
        }
        
        if(yesx== (n-1) || yesy ==(n-1)){
            Console.WriteLine("YES");
        }else
            Console.WriteLine("NO");
    }
}