#include<fstream>
#include<cmath>
using namespace std;
ifstream in("triang.in");
ofstream out("triang.out");
struct ura
{
    double x,y;
};
ura p[1500];
double dist(ura a,ura b)
{
    return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
}
bool comparedoub(double a,double b)
{
    if(abs(a-b)<0.001)
        return 1;
    else
        return 0;
}
int main()
{
    int n;
    in>>n;
    int nr=0;
    for(int i=0; i<n; i++)
    {
        in>>p[i].x>>p[i].y;
    }
    double aux;
    int i,j,k,auxnr=0;
    for(i=0; i<n-2; i++)
    {
        for(j=i+1; j<n-1; j++)
        {
            aux=dist(p[i],p[j]);
            auxnr=0;
            for(k=j+1; k<n; k++)
            {
                if(comparedoub(aux,dist(p[i],p[k])))
                    if(comparedoub(aux,dist(p[j],p[k])))
                    {
                        {
                            nr++;
                            auxnr++;
                        }
                    }
                if(auxnr==2)
                    break;
            }
        }
    }
    out<<nr;
    return 0;
}