#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  ios::sync_with_stdio(false);
  cin >> n;
  vector<vector<int> > p;
  p.resize(n);
  long long res = 0;
  for (int i = 0; i < n; i++) {
    p[i].resize(2);
    cin >> p[i][0] >> p[i][1];
  }
  long long howmany = 0;
  for (int i = 0; i < n; i++) {
    map<double, int> m;
    m.clear();
    map<double, int>::iterator it;
    for (int j = i + 1; j < n; j++) {
      if (p[i][0] == p[j][0])
        m[1000]++;
      else
        m[(p[j][1] * 1.0 - p[i][1]) / (p[j][0] * 1.0 - p[i][0])]++;
    }
    howmany = 0;
    for (it = m.begin(); it != m.end(); it++) {
      howmany += (it->second) * 1LL * (n - i - 1 - it->second);
    }
    howmany /= 2;
    res += howmany;
  }
  cout << res << endl;
  return 0;
}
