#include <bits/stdc++.h>
using namespace std;
int x[2005], y[2005];
int v[2005];
int main() {
  long long n;
  cin >> n;
  if (n < 3) {
    cout << "0" << endl;
    return 0;
  }
  long long con = 0;
  for (int i = 0; i < n; i++) cin >> x[i] >> y[i];
  long long ans = n * (n - 1) / 2 * (n - 2) / 3;
  for (int i = 0; i < n - 2; i++)
    for (int j = i + 1; j < n - 1; j++)
      for (int k = j + 1; k < n; k++) {
        int a = (y[k] - y[j]) * (x[j] - x[i]);
        int b = (x[k] - x[j]) * (y[j] - y[i]);
        if (a == b) ans--;
        con++;
      }
  cout << ans << endl;
  return 0;
}
