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[] X = new int[n];
        int[] Y = new int[n];
        int slope = 0, temp = 0;
        boolean isLine = true;
        for(int a0 = 0; a0 < n; a0++){
            X[a0] = in.nextInt();
            Y[a0] = in.nextInt();            
        }
        for(int a1=1; a1<n;a1++){
            
            if((X[a1]-X[a1-1])==0) slope = -1;
            else{ slope = (Y[a1]-Y[a1-1])/(X[a1]-X[a1-1]);}
            if(temp!=slope&&a1>1) isLine = false;
            temp = slope;
        }
        //System.out.println(isLine);
        if(isLine) System.out.println("YES");
        else System.out.println("NO");
    }
}