#include <fstream>
#include <cstdlib>
using namespace std;

ifstream is("trapez.in");
ofstream os("trapez.out");

struct punct{
    int x, y;
} p[1001];

int n;
int answ;

bool PARALELE(punct a1, punct a2, punct b1, punct b2);

int main()
{
    is >> n;
    for ( int i = 1; i <= n; ++i )
        is >> p[i].x >> p[i].y;
    for ( int i1 = 1; i1 <= n - 1; ++i1 )
        for ( int j1 = i1 + 1; j1 <= n; ++j1 )
            for ( int i2 = 1; i2 <= n - 1; ++i2 )
                for ( int j2 = i2 + 1; j2 <= n; ++j2 )
                {
                    if ( i1 == j1 || i1 == i2 || i1 == j2 || j1 == i2 || j1 == j2 || i1 == i2 )
                        continue;
                    if ( PARALELE(p[i1], p[j1], p[i2], p[j2]) )
                    {
                        ++answ;
                        //os << i1 << " " << j1 << " " << i2 << " " << j2 << "\n";
                    }
                }
    os << answ / 2;
    is.close();
    os.close();
    return 0;
}

bool PARALELE(punct a1, punct a2, punct b1, punct b2)
{
    if ( a1.x == a2.x || b1.x == b2.x )
    {
        if ( a1.x == a2.x && b1.x == b2.x )
            return true;
        return false;
    }
    if ( (a1.x - a2.x) * (b1.y - b2.y) == (b1.x - b2.x) * (a1.y - a2.y) )
        return true;
    return false;
}