#include <bits/stdc++.h>
using namespace std;
const int oo = 0x3f3f3f3f;
const int maxn = 2020;
struct Point {
  int x, y;
} a[maxn];
inline bool operator==(const Point& a, const Point& b) {
  return a.x == b.x && a.y == b.y;
}
inline bool cmpx(const Point& a, const Point& b) {
  if (a.x == b.x) return a.y < b.y;
  return a.x < b.x;
}
inline bool cmpy(const Point& a, const Point& b) {
  if (a.y == b.y) return a.x < b.x;
  return a.y < b.y;
}
int n;
long long ans = 0;
int cross(Point a, Point b) { return a.x * b.y - a.y * b.x; }
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d%d", &a[i].x, &a[i].y);
  sort(a + 1, a + n + 1, cmpx);
  if (n <= 2) {
    printf("0\n");
    return 0;
  }
  ans = (long long)n * (n - 1) / 2 * (n - 2) / 3;
  for (int i = 1; i < n - 1; i++) {
    for (int j = i + 1; j < n; j++) {
      int fz = a[j].y - a[i].y;
      int fm = a[j].x - a[i].x;
      Point ysy1, ysy2;
      ysy1.x = fm;
      ysy1.y = fz;
      for (int k = j + 1; k <= n; k++) {
        ysy2.x = a[k].x - a[i].x;
        ysy2.y = a[k].y - a[i].y;
        if (cross(ysy1, ysy2) == 0) ans--;
      }
    }
  }
  printf("%I64d\n", ans);
  return 0;
}
