import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
   public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[][] p= new int[n][2];
        int flag = 0;         
        for(int a0 = 0; a0 < n; a0++){
                p[a0][0]= in.nextInt();
                p[a0][1]= in.nextInt();
        }
        for(int i=0 ; i<n-2 ; i++){
            int Y = (p[i][1] - p[0][1])*(p[1][0]- p[0][0]);
            int X = (p[i][0] - p[0][0])*(p[1][1]- p[0][1]);
            if( X != Y  ){
                flag = 1;
            }
        }
        if(flag == 1){
            System.out.println("NO");
        }else{
            System.out.println("YES");
        }
    }

}