//
//  main.cpp
//  Patrate3
//
//  Created by Mara Dascalu on 25/05/2021.
//IDEE PRELUATA DIN PRIMUL RASPUNS : //https://math.stackexchange.com/questions/958381/how-to-find-the-number-of-squares-formed-by-given-lattice-points

#include <iostream>
#include <fstream>
#include <set>

using namespace std;

ifstream input("patrate3.in");
ofstream output("patrate3.out");

const int n_max = 1000;
set<pair<int, int>> coordonate;
pair<int, int> a[n_max+1];
int n, patrat;
double x,y;

void verifPatrat (pair<int, int> x, pair<int, int> y)
{
    int dif_x, dif_y;
    dif_x = x.first - y.first;
    dif_y = y.second - x.second;
    if (coordonate.find({x.first + dif_y , x.second + dif_x}) != coordonate.end() && coordonate.find({y.first + dif_y, y.second + dif_x}) != coordonate.end())
        patrat++;
}

int main(int argc, const char * argv[]) {
    input>>n;
    for (int i = 1; i <= n; i++)
    {
        input>>x>>y;
        a[i].first = round(x * 10000);
        a[i].second = round(y * 10000);
        coordonate.insert(a[i]);
    }
    
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            if (i != j)
            {
                verifPatrat(a[i], a[j]);
            }
    output<<patrat/4;
}