#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int N;
  int result = 0;
  cin >> N;
  vector<pair<int, int>> points;
  for (int i = 0; i < N; i++) {
    int first, second;
    cin >> first >> second;
    points.push_back(make_pair(first, second));
  }
  for (int i = 0; i < points.size(); i++) {
    for (int j = 0; j < i; j++) {
      for (int k = 0; k < j; k++) {
        if (points[i].first * points[j].second +
                points[j].first * points[k].second +
                points[k].first * points[i].second -
                points[i].second * points[j].first -
                points[j].second * points[k].first -
                points[k].second * points[i].first !=
            0) {
          result++;
        }
      }
    }
  }
  cout << result;
  return 0;
}
