#include <bits/stdc++.h>
using namespace std;
const int N = 2000;
vector<pair<int, int> > vec(N);
bool slp(pair<int, int> p1, pair<int, int> p2, pair<int, int> p3) {
  if ((p3.second - p2.second) * (p2.first - p1.first) ==
      (p3.first - p2.first) * (p2.second - p1.second))
    return false;
  return true;
}
int main() {
  int n;
  long long int cnt;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d%d", &vec[i].first, &vec[i].second);
  cnt = 0;
  for (int i = 0; i < n; i++) {
    for (int j = i + 1; j < n; j++) {
      for (int k = j + 1; k < n; k++) {
        bool p = slp(vec[i], vec[j], vec[k]);
        if (p) cnt++;
      }
    }
  }
  cout << cnt;
}
