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[] xs = new int[n];
        int[] ys = 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]);
            xs[a0] = x;
            ys[a0] = y;
        }
        
        bool result = true;
        for (int i = 2; i < xs.Length; i++)
        {
            var left = (xs[0]- xs[i])*(ys[1]-ys[i]);
            var right = (xs[1] - xs[i]) * (ys[0] - ys[i]);
            if (left != right)
            {
                result = false;
                break;
            }
        }
        
        Console.WriteLine(result ? "YES" : "NO");
    }
}