#include <bits/stdc++.h>
using namespace std;
template <typename T, typename T1>
ostream &operator<<(ostream &out, pair<T, T1> obj) {
  return out << "(" << obj.first << "," << obj.second << ")";
}
template <typename T, typename T1>
ostream &operator<<(ostream &out, map<T, T1> cont) {
  typename map<T, T1>::const_iterator itr = cont.begin();
  typename map<T, T1>::const_iterator ends = cont.end();
  for (; itr != ends; ++itr) out << *itr << " ";
  out << endl;
}
template <typename T,
          template <typename ELEM, typename ALLOC = allocator<ELEM>> class CONT>
ostream &operator<<(ostream &out, CONT<T> cont) {
  typename CONT<T>::const_iterator itr = cont.begin();
  typename CONT<T>::const_iterator ends = cont.end();
  for (; itr != ends; ++itr) out << *itr << " ";
  out << endl;
}
template <typename T>
T gcd(T a, T b) {
  T min_v = min(a, b);
  T max_v = max(a, b);
  while (min_v) {
    T temp = max_v % min_v;
    max_v = min_v;
    min_v = temp;
  }
  return max_v;
}
int N;
int X_axe[2010], Y_axe[2010];
long long collinear;
map<pair<int, int>, long long> keep_slopes;
void fix_slope(pair<int, int> &slp) {
  long long val = gcd(abs(slp.first), abs(slp.second));
  if (slp.first * slp.second >= 0)
    slp = make_pair(abs(slp.first) / val, abs(slp.second) / val);
  else if (slp.first * slp.second < 0)
    slp = make_pair(-abs(slp.first) / val, abs(slp.second) / val);
}
int main() {
  scanf("%d", &N);
  for (auto i = 0 - (0 > N); i != N - (0 > N); i += 1 - 2 * (0 > N))
    scanf("%d%d", X_axe + i, Y_axe + i);
  for (auto i = 0 - (0 > N); i != N - (0 > N); i += 1 - 2 * (0 > N)) {
    keep_slopes.clear();
    for (auto j = i + 1 - (i + 1 > N); j != N - (i + 1 > N);
         j += 1 - 2 * (i + 1 > N)) {
      pair<int, int> slope =
          make_pair(Y_axe[i] - Y_axe[j], X_axe[i] - X_axe[j]);
      fix_slope(slope);
      if (keep_slopes.count(slope))
        ++keep_slopes[slope];
      else
        keep_slopes.insert(make_pair(slope, 1));
    }
    for (auto v : keep_slopes) collinear += v.second * (v.second - 1) / 2;
  }
  long long ans = (long long)N * (long long)(N - 1) * (long long)(N - 2) / 6;
  ans -= collinear;
  printf("%I64d\n", ans);
  return 0;
}
