#include <bits/stdc++.h>
using namespace std;
inline int Set(int N, int pos) { return N = N | (1 << pos); }
inline int Reset(int N, int pos) { return N = N & ~(1 << pos); }
inline bool check(int N, int pos) { return (bool)(N & (1 << pos)); }
template <class T>
T gcd(T a, T b) {
  if (b == 0) return 0;
  return (a % b == 0) ? b : gcd(b, a % b);
}
template <class T>
T lcm(T a, T b) {
  return (a / gcd(a, b)) * b;
}
template <class T>
bool is_prime(T n) {
  if ((n % 2 == 0 && n > 2) || n < 2) return 0;
  for (T i = 3; i * i <= n; i = i + 2) {
    if (n % i == 0) return 0;
  }
  return 1;
}
pair<int, int> a[2010];
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> a[i].first >> a[i].second;
  int sum = 0;
  for (int i = 0; i < n; i++) {
    map<pair<int, int>, int> M;
    for (int j = i + 1; j < n; j++) {
      pair<int, int> tmp(a[i].second - a[j].second, a[i].first - a[j].first);
      int g = gcd(tmp.first, tmp.second);
      if (g) {
        tmp.second /= g;
        tmp.first /= g;
        M[tmp]++;
      } else
        M[make_pair(0, 0)]++;
    }
    vector<int> v;
    for (typeof((M).begin()) it = (M).begin(); it != (M).end(); it++)
      v.push_back(it->second);
    for (int j = 0; j < v.size(); j++) {
      for (int k = j + 1; k < v.size(); k++) {
        sum += (v[j] * v[k]);
      }
    }
  }
  cout << sum << endl;
  return 0;
}
