/* #region Head */

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

using ll = long long;
using ull = unsigned long long;
using pll = pair<ll, ll>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vd = vector<double>;
using vvd = vector<vd>;
using vs = vector<string>;
using vvs = vector<vs>;
// using rat = boost::rational<ll>;

#define REP(i, m, n) for (ll i = (m), i##_len = (ll)(n); i < i##_len; ++(i))
#define REPM(i, m, n) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; ++(i))
#define REPR(i, m, n) for (ll i = (m), i##_min = (ll)(n); i >= i##_min; --(i))
#define REPD(i, m, n, d) for (ll i = (m), i##_len = (ll)(n); i < i##_len; i += (d))
#define REPMD(i, m, n, d) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; i += (d))
#define REPI(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
#define ALL(x) begin(x), end(x)
#define SIZE(x) ((ll)(x).size())

constexpr ll INF = 1'010'000'000'000'000'017LL;
constexpr ll MOD = 1'000'000'007LL; // 1e9 + 7
constexpr double EPS = 1e-12;
constexpr double PI = 3.14159265358979323846;

// vector入力
template <typename T>
istream &operator>>(istream &is, vector<T> &vec)
{
    for (T &x : vec)
        is >> x;
    return is;
}

// vector出力
template <typename T>
ostream &operator<<(ostream &os, vector<T> &vec)
{
    ll len = SIZE(vec);
    os << "{";
    for (int i = 0; i < len; i++)
        os << vec[i] << (i == len - 1 ? "" : ", ");
    os << "}";
    return os;
}

// pair入力
template <typename T, typename U>
istream &operator>>(istream &is, pair<T, U> &pair_var)
{
    is >> pair_var.first >> pair_var.second;
    return is;
}

// pair出力
template <typename T, typename U>
ostream &operator<<(ostream &os, pair<T, U> &pair_var)
{
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}

// map出力
template <typename T, typename U>
ostream &operator<<(ostream &os, map<T, U> &map_var)
{
    os << "{";
    REPI(itr, map_var)
    {
        os << *itr;
        itr++;
        if (itr != map_var.end())
            os << ", ";
        itr--;
    }
    os << "}";
    return os;
}

// set 出力
template <typename T>
ostream &operator<<(ostream &os, set<T> &set_var)
{
    os << "{";
    REPI(itr, set_var)
    {
        os << *itr;
        itr++;
        if (itr != set_var.end())
            os << ", ";
        itr--;
    }
    os << "}";
    return os;
}

// dump
#define DUMPOUT cerr
void dump_func()
{
    DUMPOUT << endl;
}
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&... tail)
{
    DUMPOUT << head;
    if (sizeof...(Tail) > 0)
    {
        DUMPOUT << ", ";
    }
    dump_func(move(tail)...);
}

// _max の終端．
template <class Head>
ll _max(Head &&head)
{
    return head;
}
// 最大値を求める．max({}) の代わり．これにしないと vscode が壊れる．
template <class Head, class... Tail>
ll _max(Head &&head, Tail &&... tail)
{
    return max((ll)head, _max((tail)...));
}

// _min の終端．
template <class Head>
ll _min(Head &&head)
{
    return head;
}
// 最小値を求める．min({}) の代わり．これにしないと vscode が壊れる．
template <class Head, class... Tail>
ll _min(Head &&head, Tail &&... tail)
{
    return min((ll)head, _min((tail)...));
}

// chmax (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>>
bool chmax(T &xmax, const U &x, Comp comp = {})
{
    if (comp(xmax, x))
    {
        xmax = x;
        return true;
    }
    return false;
}

// chmin (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>>
bool chmin(T &xmin, const U &x, Comp comp = {})
{
    if (comp(x, xmin))
    {
        xmin = x;
        return true;
    }
    return false;
}

// container 内の最初の element のインデックスを探す
template <class Container>
ll indexof(const Container &container, const typename Container::value_type &element)
{
    auto iter = find(container.begin(), container.end(), element);
    size_t index = distance(container.begin(), iter);
    if (index == container.size())
    {
        index = -1;
    }
    return index;
}

// ローカル用
// #define DEBUG_

#ifdef DEBUG_
#define DEB
#define dump(...)                                                       \
    DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                     \
            << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" \
            << endl                                                     \
            << "    ",                                                  \
        dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)
#endif

struct AtCoderInitialize
{
    static constexpr int IOS_PREC = 15;
    static constexpr bool AUTOFLUSH = false;

    AtCoderInitialize()
    {
        ios_base::sync_with_stdio(false);
        cin.tie(nullptr);
        cout.tie(nullptr);
        cout << fixed << setprecision(IOS_PREC);
        if (AUTOFLUSH)
            cout << unitbuf;
    }
} ATCODER_INITIALIZE;

/* #endregion */

struct MyPoint
{
    ll quadrant;
    ll x;
    ll y;
    bool operator<(const MyPoint &another) const
    {
        if (quadrant == another.quadrant) // 同じ象限内
        {
            // 辺々に x, another.x が掛けられるので，これらの正負によって不等号の向きが変わる
            if (x * another.x == 0.0) // どちらかの x が 0
                return y < 0 ? x < another.x : x > another.x;
            else if (x * another.x > 0) // x が同符号
                return y * another.x < x * another.y;
            else
                return y * another.x > x * another.y;
        }
        else
        {
            return quadrant < another.quadrant;
        }
    };
    bool operator>(const MyPoint &another) const
    {
        if (quadrant == another.quadrant) // 同じ象限内
        {

            if (x * another.x == 0.0) // どちらかの x が 0
                return y < 0 ? x > another.x : x < another.x;
            else if (x * another.x > 0)
                return y * another.x > x * another.y;
            else
                return y * another.x < x * another.y;
        }
        else
        {
            return quadrant > another.quadrant;
        }
    };
};
ostream &operator<<(ostream &os, MyPoint &point)
{
    os << "(" << point.quadrant << ", " << point.y << "/" << point.x << ")";
    return os;
};

ll get_quadrant(ll x, ll y)
{
    if (x == 0)
        return y > 0 ? 2 : 0;
    else if (y == 0)
        return x > 0 ? 1 : -1;
    else
        return x > 0 ? (y > 0 ? 1 : 0) : (y > 0 ? 2 : -1);
}

/**
ユークリッド平面上に存在する n 個の点 P_1 ... P_n が与えられます。
n 個の点から 3 つ選ぶ組合せのうち、その 3 点から構成される三角形の内部(辺上を除く)に点 (0, 0) が含まれるものは何通りありますか？
 */
void solve()
{
    ll n;
    cin >> n;
    vll px(n), py(n);
    REP(i, 0, n)
    {
        cin >> px[i] >> py[i];
    }
    vector<MyPoint> tans(n);
    REP(i, 0, n)
    {
        tans[i] = {get_quadrant(px[i], py[i]), px[i], py[i]}; // make_pair(rat(py[i], px[i]), py[i]);
    }
    sort(ALL(tans));
    REP(i, 0, n)
    {
        if (tans[i].quadrant <= 0)
            tans.push_back({tans[i].quadrant + 4, tans[i].x, tans[i].y});
        else
            break;
    }
    dump(tans);
    ll cnt = 0, cnttmp;
    REP(i, 0, n - 1)
    {
        MyPoint left = tans[i];
        MyPoint left2 = {left.quadrant + 2, -left.x, -left.y};
        auto iter1 = upper_bound(ALL(tans), left2); // left2 より大きい最初の要素
        auto iter2 = lower_bound(ALL(tans), left2); // left2 以上の最初の要素
        REP(j, i + 1, n)
        {
            MyPoint right = tans[j];
            if (left.y * right.x == left.x * right.y)
                continue;
            if (right < left2)
            {
                // (left + PI, right + PI) を探せばよい
                MyPoint right2 = {right.quadrant + 2, -right.x, -right.y};
                auto iter3 = lower_bound(ALL(tans), right2);
                cnttmp = distance(iter1, iter3);
                // if (cnttmp > 0)
                cnt += cnttmp;
                dump(left2, right2, *iter1, *iter3);
            }
            else
            {
                // (right - PI, left + PI) を探せばよい
                auto iter3 = upper_bound(ALL(tans), MyPoint{right.quadrant - 2, -right.x, -right.y});
                cnttmp = distance(iter3, iter2);
                // if (cnttmp > 0)
                cnt += cnttmp;
            }
            dump(left, right, right < left2, cnttmp, cnt);
        }
    }
    cout << cnt / 3 << endl;
}

/**
 * エントリポイント．
 * @return 0.
 */
int main()
{
    solve();
    return 0;
}