#include <bits/stdc++.h>
using namespace std;
int x[2048], y[2048];
template <typename T>
T gcd(T a, T b) {
  T c;
  while (b) {
    c = b;
    b = a % b;
    a = c;
  }
  return a;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cerr.tie(0);
  long long int n;
  cin >> n;
  for (auto i = 0; i < (n); i++) cin >> x[i] >> y[i];
  long long int ans = n * (n - 1) * (n - 2) / 6;
  map<pair<int, pair<int, int> >, bitset<2048> > lines;
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      int a = y[i] - y[j];
      int b = x[j] - x[i];
      int c = x[i] * (y[j] - y[i]) + y[i] * (x[i] - x[j]);
      int g = gcd(a, gcd(b, c));
      a /= g;
      b /= g;
      c /= g;
      if (a == 0) {
        if (b == 0) {
          c = abs(c);
        } else if (b < 0) {
          b = -b;
          c = -c;
        }
      } else if (a < 0) {
        a = -a;
        b = -b;
        c = -c;
      }
      pair<int, pair<int, int> > l = make_pair(a, make_pair(b, c));
      auto it = lines.lower_bound(l);
      if (it == lines.end() || it->first != l) {
        bitset<2048> b;
        b[i] = 1;
        b[j] = 1;
        lines.insert(it, make_pair(l, b));
      } else {
        it->second[i] = 1;
        it->second[j] = 1;
      }
    }
  }
  for (auto& l : lines) {
    long long int x = l.second.count();
    ans -= x * (x - 1) * (x - 2) / 6;
  }
  cout << ans << '\n';
  return 0;
}
