#include <bits/stdc++.h>
using namespace std;
double slope(int dx, int dy) {
  if (dx == 0)
    return 2e8;
  else
    return 1.0 * dy / dx;
}
int main() {
  int n, i, j, x[2020], y[2020];
  long long ans = 0;
  map<double, int> lines[2020];
  scanf("%d", &n);
  for (i = 0; i < n; ++i) scanf("%d %d", x + i, y + i);
  for (i = 0; i < n; ++i)
    for (j = 0; j < n; ++j)
      if (i != j) ++lines[i][slope(x[j] - x[i], y[j] - y[i])];
  for (i = 0; i < n; ++i)
    for (j = i + 1; j < n; ++j)
      ans += n - lines[i][slope(x[j] - x[i], y[j] - y[i])] - 1;
  cout << ans / 3 << endl;
  return 0;
}
