#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

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

struct punct
{
    long long x, y;
}v[1000005], p[1005];

int main()
{
    int n, k = 0, nr = 0;
    fin >> n;
    for (int i = 1; i <= n; i++)
    {
        fin >> p[i].x >> p[i].y;
        for (int j = i - 1; j >= 1; j--)
        {
            k++;
            v[k].x = p[j].x - p[i].x;
            v[k].y = p[j].y - p[i].y;
            for (int q = k - 1; q >= 1; q--)
                if (v[q].x * v[k].y == v[q].y * v[k].x)
                    nr++;
        }
    }
    fout << nr << '\n';
    return 0;
}