#include <bits/stdc++.h>
using namespace std;
const int maxn = 2100;
struct point {
  int x, y;
};
long long tot;
point a[maxn];
long double ang[maxn];
long long ans;
void solve(int n) {
  int id = 0;
  for (int i = n + 1; i <= tot; ++i) {
    if (a[i].x == a[n].x)
      ang[++id] = 15101;
    else
      ang[++id] =
          ((long double)a[i].y - a[n].y) / ((long double)a[i].x - a[n].x);
  }
  sort(ang + 1, ang + id + 1);
  long long ct = 1;
  long double stand = ang[1];
  for (int i = 2; i <= id; ++i) {
    if (fabs(stand - ang[i]) < 1e-7)
      ct++;
    else {
      ans -= ct * (ct - 1) / 2;
      ct = 1;
      stand = ang[i];
    }
  }
  ans -= ct * (ct - 1) / 2;
}
int main(int argc, char* argv[]) {
  cin >> tot;
  for (int i = 1; i <= tot; ++i) {
    cin >> a[i].x >> a[i].y;
  }
  ans = tot * (tot - 1) * (tot - 2) / 6;
  for (int i = 1; i <= tot; ++i) solve(i);
  cout << ans << endl;
}
