#include <bits/stdc++.h>
using namespace std;
inline void inputfile() {}
inline void cpp_input() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
int det(int a1, int b1, int a2, int b2, int a3, int b3) {
  return (a1 * b2 + b1 * a3 + a2 * b3) - (a3 * b2 + b3 * a1 + a2 * b1);
}
int main() {
  inputfile();
  cpp_input();
  int n, x[2005], y[2005], cnt = 0;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i];
  }
  for (int(i) = (0); (i) < (n); ++(i)) {
    for (int(j) = (i + 1); (j) < (n); ++(j)) {
      for (int(k) = (j + 1); (k) < (n); ++(k)) {
        if (det(x[i], y[i], x[j], y[j], x[k], y[k]) != 0) {
          cnt++;
        }
      }
    }
  }
  cout << cnt << "\n";
  return 0;
}
