#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;

constexpr ld PI = 3.14159265358979;
constexpr ld EPS = 1e-10;

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<int> px(n), py(n);
    vector<ld> th(n);
    for (int i = 0; i < n; ++i) {
        cin >> px[i] >> py[i];
        th[i] = atan2((ld)py[i], (ld)px[i]);
    }
    sort(th.begin(), th.end());

    vector<int> tar(n);
    for (int i = 0; i < n; ++i) {
        tar[i] = lower_bound(th.begin() + i, th.end(), th[i] + PI + EPS) - th.begin();
        //cerr << tar[i] << endl;
    }

    ll ans = 0;
    for (int i = 1; i < n - 1; ++i) {
        int L = lower_bound(th.begin(), th.begin() + i, th[i] - PI + EPS) - th.begin();
        int R = lower_bound(th.begin() + i + 1, th.end(), th[i] + PI - EPS) - th.begin();
        //cerr << L << " " << i << " " << R << endl;
        for (int j = L; j < i; ++j) {
            ans += max(R - max(i + 1, tar[j]), 0);
        }
    }
    cout << ans << "\n";
    return 0;
}