#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9;
double slope(double x1, double y1, double x2, double y2) {
  if (x1 == x2) return inf;
  return (y2 - y1) / (x2 - x1);
}
int C2(int n) { return n * (n - 1) / 2; }
int main() {
  int n;
  cin >> n;
  vector<pair<double, double> > a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i].first >> a[i].second;
  }
  long long ans = 0;
  for (int i = 0; i < n; i++) {
    vector<double> b;
    for (int j = 0; j < n; j++) {
      if (i != j) {
        b.push_back(slope(a[i].first, a[i].second, a[j].first, a[j].second));
      }
    }
    sort(b.begin(), b.end());
    int curr = 1;
    for (int j = 0; j < n - 2; j++) {
      if (b[j] == b[j + 1])
        curr++;
      else
        ans -= C2(curr), curr = 1;
    }
    ans -= C2(curr);
    ans += C2(n - 1);
  }
  cout << ans / 3 << endl;
  return 0;
}
