#include <bits/stdc++.h>
using namespace std;
long long int ans = 0;
long long int takethree(long long int t) { return t * (t - 1) * (t - 2) / 6; }
long long int taketwo(long long int t) { return t * (t - 1) / 2; }
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }
map<int, int> mapper;
void ini() {
  int Total = 0;
  for (int i = 2000; i > 0; i--) {
    int ans = 0;
    for (int j = i - 1; j > 0; j--) {
      ans += j;
    }
    mapper[ans] = i;
  }
}
pair<int, int> Slope(pair<int, int> p0, pair<int, int> p1) {
  int dx = p0.first - p1.first;
  int dy = p0.second - p1.second;
  int g = gcd(dx, abs(dy));
  dx /= g;
  dy /= g;
  if (dx == 0) dy /= abs(dy);
  if (dy == 0) dx == 1;
  return pair<int, int>(dx, dy);
}
pair<int, int> data;
int main() {
  ini();
  int n;
  cin >> n;
  vector<pair<int, int> > data;
  long long int ans = takethree(n);
  for (int i = 0; i < n; i++) {
    int x, y;
    cin >> x >> y;
    data.push_back(pair<int, int>(x, y));
  }
  sort(data.begin(), data.end(), greater<pair<int, int> >());
  for (int i = 0; i < n; i++) {
    map<pair<int, int>, int> slops;
    for (int j = i + 1; j < n; j++) {
      ans -= slops[Slope(data[i], data[j])];
      slops[Slope(data[i], data[j])]++;
    }
  }
  cout << ans << endl;
  int x;
  cin >> x;
  return 0;
}
