//#include <tourist>
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
typedef long long ll;
typedef long double ld;
typedef unsigned int uint;
typedef unsigned long long ull;

typedef pair<ll, ll> p;
const int INF = 1e9;
const double eps = 1e-7;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
const long double pi = 4 * atan(1);
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
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 (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//g++ yarudake.cpp -std=c++17 -I .
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;
    cin >> n;
    vector<ll> x(n), y(n);
    vector<ld> argv;
    rep(i, n)
    {
        cin >> x[i] >> y[i];
        argv.push_back(atan2(y[i], x[i]));
        argv.push_back(atan2(y[i], x[i]) + 2 * pi);
        argv.push_back(atan2(y[i], x[i]) + 4 * pi);
    }
    //debug(argv);
    sort(ALL(argv));
    ll ans = 0;
    rep(i, n)
    {
        int j = i;
        while (argv[j] - argv[i] <= pi)
            j++; //鋭角である範囲
        int y = j;
        for (int k = i + 1; k < j; k++)
        {
            if(argv[k]-argv[i]>=pi)continue;
            while (argv[y] - argv[k] < pi-1e-12&&argv[y]-argv[i]>pi+1e-12)
            {
                //cout<<i<<" "<<k<<" "<<y<<"\n";
                //cout << argv[y] - argv[k] << "\n";
                y++;
            }

            ans += y - j;
        }
    }
    //cout << ans << "\n";
    cout << ans / 3 << "\n";
    //debug(argv);
}