#include <bits/stdc++.h>
using namespace std;
int x[2020], y[2020], n;
int main() {
  cin >> n;
  long long ans = 0;
  for (int i = 1; i <= n; i++) cin >> x[i] >> y[i];
  for (int i = 1; i <= n; i++)
    for (int j = i + 1; j <= n; j++)
      for (int k = j + 1; k <= n; k++)
        if ((x[j] - x[i]) * (y[k] - y[i]) - (y[j] - y[i]) * (x[k] - x[i]) != 0)
          ans++;
  cout << ans << endl;
  return 0;
}
