#include <bits/stdc++.h>
using namespace std;
struct Point {
  int x, y;
  Point(int x = 0, int y = 0) : x(x), y(y) {}
  Point operator+(const Point& p) const { return Point(x + p.x, y + p.y); }
  Point operator-(const Point& p) const { return Point(x - p.x, y - p.y); }
  void read() { scanf("%d%d", &x, &y); }
} a[2005];
bool ok(int i, int j, int k) {
  Point e1 = a[i] - a[j];
  Point e2 = a[i] - a[k];
  if (e1.x * e2.y - e1.y * e2.x == 0) return false;
  return true;
}
int main() {
  int n;
  while (~scanf("%d", &n)) {
    for (int i = 0; i < n; i++) a[i].read();
    long long cnt = 0;
    for (int i = 0; i < n; i++)
      for (int j = i + 1; j < n; j++)
        for (int k = j + 1; k < n; k++)
          if (ok(i, j, k)) cnt++;
    printf("%I64d\n", cnt);
  }
  return 0;
}
