#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 14;
const double inf = 1e99;
int n, ans, x[maxn], y[maxn];
map<double, set<double> > ms;
int main() {
  ios::sync_with_stdio(0), cin.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i];
    for (int j = 0; j < i; j++)
      if (x[j] == x[i])
        ms[inf].insert(x[i]);
      else {
        double m = (y[i] - y[j]) / double(x[i] - x[j]);
        ms[m].insert(y[i] - x[i] * (y[i] - y[j]) / double(x[i] - x[j]));
      }
  }
  int cnt = 0;
  long long ans = 0;
  for (auto [a, s] : ms) {
    ans += (long long)s.size() * cnt;
    cnt += s.size();
  }
  cout << ans << '\n';
}
