#include <bits/stdc++.h>

#include <unistd.h>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
 
 
typedef long long ll;
#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx_ori[4] = { -1,0, 1,0 }, dy_ori[4] = { 0,1,0,-1 };
int dx[4] = {0, 0, 0, 0}, dy[4] = {0, 0, 0, 0};
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
//const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

bool cmp(pii a, pii b) {
  double ta = atan2(a.second, a.first), tb = atan2(b.second, b.first);
  if (ta < 0) ta += 2 * pi;
  if (tb < 0) tb += 2 * pi;
  return ta < tb;
}

signed main() {
  int n;
  cin >> n;
  
  vector<pii> xy;
  rep (i, n) {
    int x,y ;
    cin >> x >> y;
    if (x == 0 and y == 0) continue;
    xy.emplace_back(x, y);
  }

  n = xy.size();

  sort(all(xy), cmp);

  const double eps = 1e-9;

  vector<double> xy2(2 * n);
  rep (i, n) {
    xy2[i] = atan2(xy[i].second, xy[i].first);
    if (xy2[i] < 0) xy2[i] += 2 * pi;
  }
  rep (i, n) {
    xy2[n + i] = xy2[i] + 2 * pi;
  }
  DEBUG_VEC(xy);
  DEBUG_VEC(xy2);
  ll ans = 0;
  rep (i, n) {
    rep (j, n) {
      if (i == j) continue;
      DEBUG(pii(i, j));
      double t1 = atan2(xy[i].second, xy[i].first);
      double t2 = atan2(xy[j].second, xy[j].first);

      DEBUG(t1);
      DEBUG(t2);
      if (abs(t1 - t2) <= eps) continue;
      if (abs(abs(t1 - t2) - pi) <= eps) continue;

      if (t1 < 0) t1 += 2 * pi;
      if (t2 < 0) t2 += 2 * pi;
      
      t1 = t1 + pi;
      t2 = t2 + pi;
      if (t1 >= 2 * pi) t1 -= 2 * pi;
      if (t2 >= 2 * pi) t2 -= 2 * pi;

      if (t1 > t2) {
        swap(t1, t2);
      }

      DEBUG(t1); DEBUG(t2);
      if (t2 - t1 > pi) {
        t1 += 2 * pi;
        swap(t1, t2);
      }
      assert(t2 > t1);
      assert(t2 - t1 < pi);
      
      auto itr1 = upper_bound(all(xy2), t1);
      auto itr2 = lower_bound(all(xy2), t2);
      ans += itr2 - itr1;
    }
  }
  DEBUG(ans);
  ans /= 6;
  cout << ans << endl;
}