#include <bits/stdc++.h>
using namespace std;
int Power(int base, int exp) {
  int ans = 1;
  while (exp > 0) {
    if (exp & 1) ans = (1LL * ans * base) % 1000000007;
    exp = exp >> 1;
    base = (1LL * base * base) % 1000000007;
  }
  return ans;
}
vector<map<long double, int> > p_CntS(2005);
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  cin >> n;
  long double x[n], y[n];
  for (int i = 0; i < n; i += 1) cin >> x[i] >> y[i];
  long double slope;
  for (int p1 = 0; p1 < n; p1 += 1)
    for (int p2 = 0; p2 < n; p2 += 1) {
      if (p1 == p2) continue;
      slope = y[p2] - y[p1];
      if (x[p2] - x[p1] == 0)
        p_CntS[p1][600.0]++;
      else
        p_CntS[p1][300.0 + slope / (x[p2] - x[p1])]++;
    }
  long long int ans = (1LL * n * (n - 1) * (n - 2)) / 6, ans_ = 0;
  int cnt;
  for (int i = 0; i < n; i += 1) {
    map<long double, int>::iterator it = p_CntS[i].begin();
    while (it != p_CntS[i].end()) {
      cnt = (*it).second;
      ans_ += 1LL * cnt * (cnt - 1) / 2;
      it++;
    }
  }
  cout << ans - ans_ / 3 << '\n';
}
