#include <bits/stdc++.h>
using namespace std;
int n;
int x[2000], y[2000];
tuple<int, int, int> line(int x1, int y1, int x2, int y2) {
  return make_tuple(y1 - y2, x2 - x1, x1 * y2 - x2 * y1);
}
long long slow() {
  long long total = 1LL * n * (n - 1) * (n - 2) / 6;
  for (int i = 0; i < n; ++i)
    for (int j = i + 1; j < n; ++j)
      for (int k = j + 1; k < n; ++k) {
        int a1, a2, a3;
        tie(a1, a2, a3) = line(x[i], y[i], x[j], y[j]);
        if (a1 * x[k] + a2 * y[k] + a3 == 0) --total;
      }
  return total;
}
long long fast() {
  map<tuple<int, int, int>, set<pair<int, int>>> mp;
  for (int i = 0; i < n; ++i)
    for (int j = i + 1; j < n; ++j) {
      auto x1 = line(x[i], y[i], x[j], y[j]);
      mp[x1].insert({x[i], y[i]});
      mp[x1].insert({x[j], y[j]});
    }
  long long total = 1LL * n * (n - 1) * (n - 2) / 6;
  for (auto& z : mp) {
    int n1 = z.second.size();
    total -= 1LL * n1 * (n1 - 1) * (n1 - 2) / 6;
  }
  return total;
}
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    scanf("%d %d", x + i, y + i);
  }
  printf("%lld\n", slow());
}
