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[] xPoints = new int[n];
        int[] yPoints = 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]);
            xPoints[a0] = x;
            yPoints[a0] = y;
        }
        
        bool horizontal = true;
        bool vertical = true;
        
        for (int i = 1; i < n; i++)
        {
            for (int j = 0; j < n; j++)
            {
                if (xPoints[i] != xPoints[j])
                    horizontal = false;
                
                if (yPoints[i] != yPoints[j])
                    vertical = false;
            }
        }
        
        if (horizontal || vertical)
            Console.WriteLine("YES");
        else
            Console.WriteLine("NO");
    }
}