#include <fstream>
#include <set>
#include <vector>
#include <cmath>

using namespace std;

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

struct point {
	double x, y;

	bool operator<(const point& other) const {
		if (this->x == other.x) {
			return this->y < other.y;
		}
		return this->x < other.x;
	}

	point() {}
	point(const double& _x, const double& _y) : x(_x), y(_y) {}
};

int n, ans;
double x, y;
vector<point> points;
set<point> fr;

inline void approx(double& val) {
	val = round(val * 10000.0) / 10000.0;
}

void solve(point a, point b) {
	point mid((a.x + b.x) / 2, (a.y + b.y) / 2);

	double len = sqrt(pow(a.x - b.x, 2) + pow(a.y - b.y, 2));
	double dist = len * sqrt(3) / 2.0;
	double slope = (b.y - a.y) / (b.x - a.x);

	double next_x = mid.x + dist * cos(atan(-1.0 / slope));
	double next_y = mid.y + dist * sin(atan(-1.0 / slope));

	approx(next_x);
	approx(next_y);

	cout << next_x << ' ' << next_y << '\n';

	if (fr.count(point(next_x, next_y))) {
		++ans;
	}

	next_x = mid.x - dist * cos(atan(-1.0 / slope));
	next_y = mid.y - dist * sin(atan(-1.0 / slope));

	approx(next_x);
	approx(next_y);

	cout << next_x << ' ' << next_y << '\n';

	if (fr.count(point(next_x, next_y))) {
		++ans;
	}
}

int main()
{
	cin >> n;

	for (int i = 0; i < n; ++i) {
		cin >> x >> y;

		approx(x);
		approx(y);

		cout << x << ' ' << y << '\n';

		points.emplace_back(x, y);
		fr.emplace(x, y);
	}

	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < n; ++j) {
			if (i != j) {
				solve(points[i], points[j]);
			}
		}
	}

	cout << ans / 6;

	return 0;
}