#include <fstream>
#include <iostream>
#include <vector>
#include <utility>
#include <algorithm>
#include <unordered_set>
#include <cmath>
using namespace std;
 
constexpr double epsilon = 1e-3;
 
double eq(const double a, const double b){
    return (a < b) ? b-a <= epsilon : a-b <= epsilon; }
 
double rnd(const double x){
    return x < 0 ? -rnd(-x) : floor(x + 0.5); }
 
struct point{
    double x, y;
    constexpr point(): x(0), y(0){}
    point(const double X, const double Y):
        x(X), y(Y){}
    bool operator==(const point& rhs)const{
        return eq(x, rhs.x) && eq(y, rhs.y); }
    bool operator<(const point& rhs)const{
        return (!eq(x, rhs.x) && x < rhs.x) ||
            (eq(x, rhs.x) && !eq(y, rhs.y) && y < rhs.y); } };
 
ostream& operator<<(ostream& lhs, const point& rhs){
    lhs << rhs.x << ' ' << rhs.y;
    return lhs; }
 
point operator-(const point a, const point b){
    return point(a.x - b.x, a.y - b.y); }

point operator+(const point a, const point b){
    return point(a.x + b.x, a.y + b.y); }

constexpr double sqrt3_pe_2 = 0.866025403784439;

point rotate_60(const point a){
	return point(a.x/2 - a.y * sqrt3_pe_2, a.x * sqrt3_pe_2 + a.y/2); }

point rotate_minus_60(const point a){
	return point(a.x/2 + a.y * sqrt3_pe_2, -a.x * sqrt3_pe_2 + a.y/2); }

pair<point, point> make_pts(const point a, const point b){
	const point r = b-a, v1 = rotate_60(r), v2 = rotate_minus_60(r);
	return  make_pair(a + v1, a + v2); }
 
int main(){
    ifstream f("triang.in");
    ofstream g("triang.out");
    int n;
    f >> n;
    vector<point> puncte;
    puncte.reserve(n);
    for(int i = 0; i < n; ++i){
        double x, y;
        f >> x >> y;
        puncte.emplace_back(x, y); }
    sort(begin(puncte), end(puncte));
    int rez = 0;
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j){
            if(i != j){
                const auto pts = make_pts(puncte[i], puncte[j]);
                if(binary_search(begin(puncte), end(puncte), pts.first)){
                    ++rez; }
                if(binary_search(begin(puncte), end(puncte), pts.second)){
                    ++rez; } } } }
    g << rez/6;
    return 0; }