#include <fstream>
#include <cmath>
#include <iostream>
/*#include <algorithm>*/
using namespace std;

struct punct{
	double x, y;
};

int N, S;
punct P[1500];

/*bool compara(punct A, punct B){
	return A.x+A.y<B.x+B.y;
}*/

bool egale(double a, double b){
	return fabs(a-b)<0.003;
}

double distanta(punct A, punct B){
	return sqrt((A.x-B.x)*(A.x-B.x)+(A.y-B.y)*(A.y-B.y));
}

/*bool gaseste(punct A, punct B, int i, double dist){
	int j, m;
	double dn, dm;

	j=N-1;
	while (i<=j){
		m=(i+j)/2;
		dn=distanta(A, P[m]); dm=distanta(B, P[m]);
		if (egale(dn, dm) && egale(dn, dist))
			return true;
		if (dn<dist)
			i=m+1;
		else
			j=m-1;
	}
	return false;
}*/

int main(){
	int i, j;

	ifstream fin ("triang.in");
	fin >> N;
	for (i=0; i<N; i++)
		fin >> P[i].x >> P[i].y;
	fin.close();

	/*sort(P, P+N, compara);*/

	/*for (i=0; i<N-2; i++)
		for (j=0; j<N-1; j++)
			if (gaseste(P[i], P[j], j+1, distanta(P[i], P[j])))
				S++;*/

	for (i=0; i<N-2; i++)
		for (j=i+1; j<N-1; j++)
			for (int k=j+1; k<N; k++)
				if (i!=j && j!=k && i!=k && egale(distanta(P[i], P[j]), distanta(P[i], P[k])) && egale(distanta(P[i], P[j]), distanta(P[j], P[k])))
					S++;

	ofstream fout ("triang.out");
	fout << S << '\n';
	fout.close();

	return 0;
}