#include <fstream>
#include <unordered_set>
#include <math.h>
#include <set>
#define MAXN 1505
#define EPS 0.0001
using namespace std;
ifstream f("triang.in");
ofstream g("triang.out");

bool is_equal(double a, double b){
	return fabs(a - b) < EPS;
}

struct Comp{
	bool operator()(pair<double, double> a, pair<double, double> b){
		if(is_equal(a.first, b.first)){
			if(is_equal(a.second, b.second))
				return 0;
			return a.second < b.second;
		}
		return a.first < b.first;
	}
};

int n, sol;
pair<double, double> v[MAXN];
//unordered_set<pair<double, double> > v_hash;
set< pair<double, double>, Comp> v_hash;

void rotate(pair<double, double> &p, double u){
	double x = p.first, y = p.second;
	p.first = x * cos(u) - y * sin(u);
	p.second = x * sin(u) + y * cos(u);
}


void solve(pair<double, double> p1, pair<double, double> p2){
	pair<double, double> p2t = make_pair(p2.first - p1.first, p2.second - p1.second);
	pair<double, double> p3;
	double u = atan2(p2t.second, p2t.first);
	
	rotate(p2t, -u);
		
	p3.first = p2t.first / 2;
	p3.second = sqrt(3 * (p2t.first * p2t.first + p2t.second * p2t.second)) / 2;
	
	rotate(p3, u);
	p3.first += p1.first; p3.second += p1.second;
	
	if(v_hash.find(p3) != v_hash.end())
		sol++;
	
	p3.first = p2t.first / 2;
	p3.second = -sqrt(3 * (p2t.first * p2t.first + p2t.second * p2t.second)) / 2;
	
	rotate(p3, u);
	p3.first += p1.first; p3.second += p1.second;
	
	if(v_hash.find(p3) != v_hash.end())
		sol++;
	
}

int main(){
	int i, j;

	f >> n;
	for(i = 1; i <= n; i++){
		f >> v[i].first >> v[i].second;
		for(j = 1; j < i; j++)
			solve(v[i], v[j]);
		v_hash.insert(v[i]);
	}

	g << sol / 2 << '\n';

	f.close();
	g.close();
	return 0;
}