#include <bits/stdc++.h>
using namespace std;
const int N = 2005;
int n;
int x[N], y[N];
int main() {
  while (cin >> n) {
    for (int i = 0; i < n; ++i) cin >> x[i] >> y[i];
    if (n < 3) {
      cout << 0 << endl;
      continue;
    }
    long long ans = 0;
    for (int i = 0; i < n; ++i) {
      map<int, int> my;
      for (int j = 0; j < n; ++j) {
        if (i == j) continue;
        int tmp = 0x3f3f3f3f;
        if (y[i] != y[j]) tmp = 1000000 * (x[i] - x[j]) / (y[i] - y[j]);
        my[tmp]++;
      }
      map<int, int>::iterator iter;
      for (iter = my.begin(); iter != my.end(); ++iter) {
        ans += iter->second * (n - iter->second - 1);
      }
    }
    cout << ans / 6 << endl;
  }
  return 0;
}
