#include <bits/stdc++.h>
using namespace std;

string to_string(string s) { return '"' + s + '"'; }
string to_string(bool b) { return b ? "true" : "false"; }
template <size_t N> string to_string(bitset<N> bs) {
  string res;
  for (size_t i = 0; i < N; ++i) res += '0' + bs[i];
  return res;
}
string to_string(vector<bool> v) {
  string res = "{";
  for (bool e : v) res += to_string(e) + ", ";
  return res += "}";
}

template <class T, class U> string to_string(pair<T, U> p);
template <class C> string to_string(C c) {
  string res = "{";
  for (auto e : c) res += to_string(e) + ", ";
  return res += "}";
}
template <class T, class U> string to_string(pair<T, U> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

void debug() { cerr << '\n'; }
template <class Head, class... Tail> void debug(Head head, Tail... tail) {
  cerr << ' ' << to_string(head), debug(tail...);
}
#ifdef LOCAL
#define DEBUG(...) cerr << "[" << #__VA_ARGS__ << "]:", debug(__VA_ARGS__)
#else
#define DEBUG(...)
#endif

constexpr long double pi = acos(-1.0L);
constexpr long double eps = 1e-15;

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int n;
  cin >> n;
  vector<long double> a;
  while (n--) {
    int x, y;
    cin >> x >> y;
    if (x == 0 and y == 0) {
      continue;
    }
    a.push_back(atan2((long double)y, x));
  }
  n = a.size();
  sort(begin(a), end(a));
  for (int i = 0; i < n; ++i) {
    a.push_back(a[i] + 2 * pi);
  }
  DEBUG(a);
  long long res = (long long)n * (n - 1) * (n - 2) / 6;
  for (int i = 0; i < n; ++i) {
    int x = lower_bound(begin(a) + i, end(a), a[i] + pi + eps) - (begin(a) + i);
    DEBUG(i, x);
    res -= (x - 1) * (x - 2) / 2;
  }
  auto cmp = [](long double l, long double r) {
    return l + eps < r;
  };
  auto tmod = [](long double x, long double mod) {
    x = fmod(x, mod);
    return x < 0 ? x + mod : x;
  };
  map<long double, int, decltype(cmp)> mp(cmp);
  for (int i = 0; i < n; ++i) {
    ++mp[a[i]];
  }
  DEBUG(res);
  for (auto e : mp) {
    long long x = e.second;
    DEBUG(e.first, x);
    long long y = mp.count(e.first + pi) ? mp[e.first + pi] : 0;
    long long z = x + y;
    res += z * (z - 1) * (z - 2) / 6;
    res -= x * (x - 1) * (x - 2) / 6;
    res -= y * (y - 1) * (y - 2) / 6;
  }
  cout << res << '\n';
}