#include <bits/stdc++.h>
using namespace std;
int INF = 2147483645;
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(0);
  long long n, i, j, k, l;
  cin >> n;
  long long a[n], b[n];
  long long ans = 0;
  for (i = 0; i < n; i++) cin >> a[i] >> b[i];
  if (n <= 2) {
    cout << "0\n";
    return 0;
  }
  ans += (n * (n - 1) * (n - 2));
  ans /= 6;
  for (i = 0; i < n; i++) {
    long long temp = 0;
    vector<double> c;
    long long x = a[i], y = b[i];
    for (j = i + 1; j < n; j++) {
      if (a[j] - x == 0) {
        c.push_back(INF);
        continue;
      }
      double m = ((double)b[j] - (double)y) / ((double)a[j] - (double)x);
      c.push_back(m);
    }
    sort(c.begin(), c.end());
    for (j = 1; j < c.size();) {
      long long cnt = 1;
      while (c[j] == c[j - 1] && j < c.size()) {
        j++;
        cnt++;
      }
      if (cnt >= 2) temp += (cnt * (cnt - 1)) / 2;
      cnt = 1;
      j++;
    }
    ans -= temp;
  }
  cout << ans << endl;
  return 0;
}
