#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  vector<int> xc(2017);
  vector<int> yc(2017);
  cin >> n;
  for (int i = 0; i < n; i++) cin >> xc[i] >> yc[i];
  long long ans = 0;
  for (int i = 0; i < n; i++)
    for (int j = i + 1; j < n; j++)
      for (int k = j + 1; k < n; k++)
        if (xc[i] * (yc[j] - yc[k]) + xc[j] * (yc[k] - yc[i]) +
                xc[k] * (yc[i] - yc[j]) !=
            0)
          ans++;
  cout << ans << endl;
  return 0;
}
