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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map.Entry;

public class B_181 {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		int n = Integer.parseInt(br.readLine());

		Edge[] edges = new Edge[n];

		for (int i = 0; i < n; i++) {
			String[] xy = br.readLine().split(" ");
			edges[i] = new Edge(Integer.parseInt(xy[0]), Integer.parseInt(xy[1]));
		}

		HashMap<String, Integer> hm = new HashMap<>();

		int count = 0;

		for (int i = 0; i < n - 1; i++) {
			for (int j = i + 1; j < n; j++) {
				double m = (1.0 * (edges[i].y - edges[j].y) / (edges[i].x - edges[j].x));
				double c = edges[i].y - m * edges[i].x;

				if (hm.containsKey(c + " " + m)) {
					int value = hm.get(c + " " + m);
					hm.put(c + " " + m, value + 1);
				} else {
					hm.put(c + " " + m, 1);
				}
			}
		}

		for (Integer value : hm.values()) {
			int points = getNoOfPoints(value);
			count += points * (points - 1) * (points - 2) / 6;
		}

		System.out.println(count);
	}

	static int getNoOfPoints(int totalLines) {
		return (int) Math.ceil(Math.sqrt(2 * totalLines));
	}
}

class Edge {
	int x, y;

	Edge(int x, int y) {
		this.x = x;
		this.y = y;
	}
}
