#include <fstream>
#include <algorithm>
using namespace std;
ifstream cin("trapez.in");
ofstream cout("trapez.out");
struct fint
{
    int x,y;
};
fint v[1005];
long long n,sum;
int main()
{
    cin>>n;
    for(int i=1;i<=n;i++)
        cin>>v[i].x>>v[i].y;
    for(int i1=1;i1<=n;i1++)
    for(int i2=1;i2<=n;i2++)
    for(int i3=1;i3<=n;i3++)
    for(int i4=1;i4<=n;i4++)
    {
        if(i1!=i2 and i1!=i3 and i1!=i4 and i2!=i3 and i2!=i4 and i3!=i4)
        {
            fint a1,a2;
            a1.x=v[i1].x-v[i2].x;
            a1.y=v[i1].y-v[i2].y;
            a2.x=v[i3].x-v[i4].x;
            a2.y=v[i3].y-v[i4].y;
            if(a1.x*a2.y==a1.y*a2.x)
                sum++;
        }
    }
    cout<<sum/8;
    return 0;
}
/**
**/