10
-2 1
2 -2
-1 -2
0 0
2 -1
0 -2
2 2
0 2
-1 -1
1 -2
 40
-8 24
2 -1
1 -18
72 -70
5 -4
-308 436
-19 40
36 -35
-178 265
-1 2
-7 30
-1 0
3 -2
200 -285
17 -16
-35 74
0 -4
-86 106
-1 4
-7 6
0 1
-5 4
-2 3
6 -5
-4 5
181 -262
76 -118
0 0
-7 18
-58 104
-5 6
-6 12
-3 4
1 0
11 -10
-86 130
-3 6
153 -236
-183 270
-33 64
 5
0 -1
0 -2
0 -3
0 -4
0 -5
 10
0 1
-1 -1
1 1
-1 0
1 -1
-2 -1
-2 2
-2 0
0 -2
0 -1
 20
-1 18
-2 5
-5 4
2 -33
9 -18
0 0
11 -22
2 0
-1 2
-4 41
1 6
1 -2
6 -12
0 1
-3 6
3 -6
3 -8
-1 4
2 -5
1 0
 10
2 1
-1 0
-2 -1
-1 1
0 2
2 -2
0 0
-2 -2
0 -2
-2 1
 20
-3 -3
0 4
-3 1
1 1
-1 2
-4 4
3 -1
-3 0
0 2
4 0
2 3
2 4
4 -3
-4 3
-1 1
1 3
-2 4
1 -2
1 -1
3 0
 3
0 0
0 -1
0 1
 10
2 1
-1 1
0 0
-3 1
-2 -3
-1 -2
-1 -1
1 2
3 -2
0 -2
 3
3 3
1 2
1 1
 4
0 0
1 0
2 0
3 0
 9
1 1
1 0
0 1
0 0
-1 0
-1 1
-1 -1
1 -1
0 -1
 7
1 1
-1 -1
1 0
0 1
-1 0
0 -1
0 0

4
 57
 4
 5
 21
 4
 10
 1
 1
 0
 2
 8
 3

import java.util.ArrayList;
import java.util.Scanner;

public class Main{
	
	public static double[] line(int x1, int y1, int x2, int y2) {
		double[] si = new double[3];
		si[0] = ((double) (y2-y1))/(x2-x1);
		si[1] = y1 - si[0]*x1;
		si[2] = 2;
		return si;
	}
	
	public static boolean sameLine(double[] a, double[] b) {
		double dif1 = (a[0] - b[0])*(a[0] - b[0]);
		double dif2 = (a[1] - b[1])*(a[1] - b[1]);
		return dif1 < 0.0000000001 && dif2< 0.0000000001;
	}
	
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		int c = 0;
		int[][] points = new int[n][2];
		ArrayList<double[]> lines = new ArrayList<double[]>();
		while (n>0) {
			n--;
			int xco = scan.nextInt();
			int yco = scan.nextInt();
			int[] point = {xco, yco};
			points[n] = point;
		}
		
		for (int i = 0; i < points.length; i++) {
			for(int j = i+1; j<points.length; j++) {
				double[] ln = line(points[i][0],points[i][1], points[j][0],points[j][1]);
				boolean added = false;
				for (double[] ln2: lines) {
					if (sameLine(ln,ln2)) {
						ln2[2]++;
						added = true;
						break;
					}	
				}
				if (!added) lines.add(ln);
			}	
		}
		for (double[] ln: lines) {
			c += ln[2] * (ln[2]-1) * (ln[2]-2) / 6;
		}
		
		System.out.println(c);
	}
}