#include <fstream>
using namespace std;

struct punct{double x,y;} v[1<<11];
int n;
const double eroare=0.001;

ifstream in("triang.in");
ofstream out("triang.out");

inline double p(double x)
{
	return x*x;
}

inline double dist(punct a,punct b)
{
	return p(a.x-b.x)+p(a.y-b.y);
}

inline bool echi(punct a,punct b,punct c)
{
	return dist(a,b)==dist(a,c) && dist(a,b)==dist(b,c);
}

int main()
{
	in>>n;
	int i,j,k,nr=0;
	for (i=1;i<=n;i++)
		in>>v[i].x>>v[i].y;
	for (i=1;i<n-1;i++)
		for (j=i+1;j<n;j++)
			for (k=1;k<=n;k++)
				nr+=echi(v[i],v[j],v[k]);
	out<<nr<<"\n";
	return 0;
}