#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:100000000000,100000000000")
using namespace std;
const double eps = 1E-9;
const double Exp = 2.718281828459045;
const double Pi = 3.1415926535897932;
const int NMAX = 2000 + 5;
const int MMAX = 100000 + 5;
const int INF = 1000000000;
const int BS = 1000000007;
template <typename T>
inline T abs(const T a) {
  if (a < 0) return -a;
  return a;
}
template <typename T>
inline T sqr(const T& a) {
  return a * a;
}
multiset<pair<int, int> > mst;
set<pair<int, int> > st;
int gcd(int x, int y) {
  if (x == 0 || y == 0) return x + y;
  if (x == y) return x;
  return gcd(x % y, y % x);
}
int main() {
  ios::sync_with_stdio(false);
  int n;
  pair<int, int> a[NMAX];
  int i, j;
  cin >> n;
  for (i = 1; i <= n; i++) {
    cin >> a[i].first >> a[i].second;
  }
  int A, B;
  long long ans = 0;
  for (i = 1; i <= n; i++) {
    st.clear();
    mst.clear();
    for (j = 1; j <= n; j++) {
      if (i == j) continue;
      A = a[i].first - a[j].first;
      B = a[i].second - a[j].second;
      int d = gcd(abs(A), abs(B));
      A /= d;
      B /= d;
      if (A == 0) {
        B = abs(B);
      } else if (A < 0) {
        A = -A;
        B = -B;
      }
      st.insert(make_pair(A, B));
      mst.insert(make_pair(A, B));
    }
    for (set<pair<int, int> >::iterator it = st.begin(); it != st.end(); it++) {
      ans += (n - 1 - mst.count(*it)) * 1ll * mst.count(*it);
    }
  }
  cout << ans / 6 << endl;
  return 0;
}
