#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define repr(i, n) for (int i = (n) - 1; i >= 0; i--)
#define range(a) a.begin(), a.end()

struct point {
  ll x, y;

  point(ll x_ = 0, ll y_ = 0) : x(x_), y(y_) {}

  friend point operator-(point a) {
    return point(-a.x, -a.y);
  }
  
  friend point operator-(point a, point b) {
    return point(a.x - b.x, a.y - b.y);
  }

  friend ll cross(point a, point b) {
    return a.x * b.y - a.y * b.x;
  }

  friend istream &operator>>(istream &i, point &a) {
    return i >> a.x >> a.y;
  }

  friend ostream &operator<<(ostream &o, point a) {
    return o << '(' << a.x << ',' << a.y << ')';
  }
};

int quadrant(point a) {
  if (a.x > 0 && a.y == 0) return 1;
  if (a.y > 0) return 2;
  if (a.x < 0 && a.y == 0) return 3;
  return 4;
}

bool lt(point a, point b) {
  if (quadrant(a) != quadrant(b)) return quadrant(a) < quadrant(b);
  return cross(a, b) > 0;
}

int main() {
  int N; cin >> N;
  vector<point> P(N);
  rep(i, N) cin >> P[i];
  sort(range(P), lt);
  ll ans = 0;
  for (int i = 0; i < N; i++) {
    for (int j = i + 1; j < N; j++) {
      if (cross(P[i], P[j]) == 0) continue;
      if (quadrant(P[i]) >= 3) continue;
      if (cross(P[j] - P[i], -P[i]) <= 0) continue;
      if (quadrant(P[j]) <= 2) {
        int l = upper_bound(P.begin() + (j + 1), P.end(), -P[i], lt) - P.begin();
        int r = lower_bound(P.begin() + (j + 1), P.end(), -P[j], lt) - P.begin();
        ans += r - l;
      } else {
        int l = upper_bound(P.begin() + (j + 1), P.end(), -P[i], lt) - P.begin();
        ans += N - l;
      }
    }
  }
  cout << ans << endl;
}