#include <bits/stdc++.h>
using namespace std;
struct zz {
  double x;
  double y;
} p[2010];
bool cmp1(zz a, zz b) {
  if (a.x == b.x) return a.y < b.y;
  return a.x < b.x;
}
struct ss {
  double k;
  double b;
} pp[2010 * 2010];
bool cmp2(ss a, ss b) {
  if (a.k == b.k) return a.b < b.b;
  return a.k < b.k;
}
long long C(int x, int k) {
  int i, j;
  long long s = 1;
  for (i = x, j = 1; i > x - k; i--, j++) s *= i, s /= j;
  return s;
}
int main() {
  int n, i, j, k;
  while (scanf("%d", &n) != EOF) {
    for (i = 0; i < n; i++) scanf("%lf%lf", &p[i].x, &p[i].y);
    sort(p, p + n, cmp1);
    k = 0;
    double x, y;
    for (i = 0; i < n - 1; i++) {
      for (j = i + 1; j < n; j++) {
        x = (p[j].x - p[i].x);
        y = (p[j].y - p[i].y);
        if (x == 0) {
          pp[k].k = 1000.0;
          pp[k].b = p[j].x;
        } else {
          pp[k].k = y / x;
          pp[k].b = p[i].y - pp[k].k * p[i].x;
        }
        k++;
      }
    }
    sort(pp, pp + k, cmp2);
    int cnt = 1, kk;
    long long num = C(n, 3);
    for (i = 0; i < k; i++) {
      if (fabs(pp[i].k - pp[i + 1].k) <= 1e-7 &&
          fabs(pp[i].b - pp[i + 1].b) <= 1e-7)
        cnt++;
      else {
        kk = (sqrt(1 + 8 * cnt) + 1) / 2;
        num -= C(kk, 3);
        cnt = 1;
      }
    }
    printf("%lld\n", num);
  }
  return 0;
}
