#include<fstream>
#include<cmath>
using namespace std;
int n,i,j,k,con;
struct punct
{
    double x,y;
}a[1501];
double d1,d2,d3;
double distanta(double x1,double y1,double x2,double y2)
{
    double rez;
    rez=sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
    if(rez<0)
    rez=-rez;
    return rez;
}
int main()
{
    ifstream f("triang.in");
    ofstream g("triang.out");
    f>>n;
    for(i=1;i<=n;i++)
    f>>a[i].x>>a[i].y;
    for(i=1;i<=n-2;i++)
    {
        for(j=i+1;j<=n-1;j++)
        {
            for(k=j+1;k<=n;k++)
            {
                d1=distanta(a[i].x,a[i].y,a[j].x,a[j].y);
                d2=distanta(a[i].x,a[i].y,a[k].x,a[k].y);
                d3=distanta(a[j].x,a[j].y,a[k].x,a[k].y);
                if(d1==d2&&d1==d3&&d2==d3)
                con++;
            }
        }
    }
    g<<con;
    return 0;
}