#include <bits/stdc++.h>
using namespace std;
struct coef {
  long a;
  long b;
  long c;
};
struct dekart {
  int x;
  int y;
};
long NOD(long a, long b) {
  a = abs(a);
  b = abs(b);
  while (a && b) {
    if (a >= b) {
      a %= b;
    } else {
      b %= a;
    }
  }
  return a | b;
}
coef func_coef(dekart wire1, dekart wire2) {
  coef aa;
  aa.a = wire1.y - wire2.y;
  aa.b = wire2.x - wire1.x;
  aa.c = wire1.x * wire2.y - wire2.x * wire1.y;
  int x = NOD(NOD(aa.a, aa.b), aa.c);
  if (x == 0) {
    x = 1;
  }
  aa.a /= x;
  aa.b /= x;
  aa.c /= x;
  if (aa.a < 0 || (aa.a == 0 && aa.b < 0)) {
    aa.a = -aa.a;
    aa.b = -aa.b;
    aa.c = -aa.c;
  }
  return aa;
}
int main() {
  map<pair<long, long>, set<long> > coef_;
  int n;
  unsigned long long ans = 0;
  unsigned long long a = 0;
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n;
  dekart wire[1001];
  for (int i = 0; i <= n - 1; i++) {
    cin >> wire[i].x >> wire[i].y;
  }
  for (int i = 0; i <= n - 1; i++) {
    for (int k = i + 1; k <= n - 1; k++) {
      coef kc = func_coef(wire[i], wire[k]);
      pair<long, long> p = make_pair(kc.a, kc.b);
      if (!coef_[p].count(kc.c)) {
        ++a;
        coef_[p].insert(kc.c);
        ans += a - coef_[p].size();
      }
    }
  }
  cout << ans;
}
