#include <bits/stdc++.h>
using namespace std;
map<pair<double, double>, bool> mark;
int n, x[1111], y[1111];
map<double, int> cnt;
long long ans;
int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i];
    for (int j = 0; j < i; j++) {
      double m = x[i] ^ x[j] ? 1. * (y[i] - y[j]) / (x[i] - x[j]) : 2e9;
      pair<double, double> p = {m, m != 2e9 ? y[i] - m * x[i] : x[i]};
      if (mark[p]) continue;
      mark[p] = true, ans += mark.size() - ++cnt[m];
    }
  }
  cout << ans;
}
