#include <iostream>
#include <set>
#include <cstdlib>

using namespace std;

struct poi
{
	int x;
	int y;

	friend bool operator<(const poi& a, const poi& b)
	{
		if (a.x == b.x)
		{
			return a.y < b.y;
		}
		return a.x < b.x;
	}
};

int main()
{
	int n;
	cin >> n;
	poi* a = (poi*)malloc(sizeof(poi) * n);
	set<poi> ss;
	for (int i = 0; i < n; i++)
	{
		cin >> a[i].x >> a[i].y;
		ss.insert(a[i]);
	}
	int possibs = 0;
	for (int i = 1; i < n; i++)
	{
		int vecx = a[i].x - a[0].x;
		int vecy = a[i].y - a[0].y;
		bool fail = false;
		for (int j = 0; j < n; j++)
		{
			poi lokfor;
			lokfor.x = a[j].x + vecx;
			lokfor.y = a[j].y + vecy;
			if (ss.find(lokfor) != ss.end())
			{
				continue;
			}

			lokfor.x = a[j].x - vecx;
			lokfor.y = a[j].y - vecy;

			if (ss.find(lokfor) != ss.end())
				continue;

			fail = true;
			break;
		}
		if (fail)
			continue;
		else
			possibs += 2;

	}
	cout << possibs << endl;
	return 0;
}