#include <bits/stdc++.h>

using namespace std;

ifstream fin("trapez.in");
ofstream fout("trapez.out");

int n;
long long ans = 0;

struct Point
{
    int x, y;
}v[1005];

int main()
{
    fin >> n;
    for (int i = 1; i <= n; ++i)
    {
        fin >> v[i].x >> v[i].y;
    }
    for (int i = 1; i <= n; ++i)
    {
        for (int j = i + 1; j <= n; ++j)
        {
            for (int i2 = 1; i2 <= n; ++i2)
            {
                for (int j2 = i2 + 1; j2 <= n; ++j2)
                {
                    if (i2 != i && i2 != j && j2 != i && j2 !=j)
                    {
                        if (1LL * (v[j].y - v[i].y) * (v[j2].x - v[i2].x) == 1LL * (v[j2].y - v[i2].y) * (v[j].x - v[i].x))
                        {
                            ++ans;
                        }
                    }
                }
            }
        }
    }
    fout << ans / 2;
    fin.close();
    fout.close();
    return 0;
}