#include <bits/stdc++.h>

using namespace std;
ifstream fin("patrate3.in");
ofstream fout("patrate3.out");

set<pair <int, int>> h; ///coordonatele punctelor --> va fi f usor de gasit un punct O(1)
pair<int, int> a[1005];

int n, sol;

void read()
{
    double x, y;
    int i;
    fin >> n;
    for(i = 1; i <= n; ++i)
    {
        fin >> x >> y;
        a[i].first = round(x * 10000);      ///pt convertire
        a[i].second = round(y * 10000);
        h.insert(a[i]);
    }
}

//va fi apelata de multe ori
inline bool square(pair <int, int> a, pair<int, int> b)
{
    int x, y;
    y = b.first - a.first;
    x = a.second - b. second;
    if(h.find({a.first + x, a.second + y}) != h.end() && h.find({b.first + x, b.second + y}) != h.end())///caut latura paralela aferenta
        return 1;
    return 0;
}
int main()
{
    read();
    int i, j;
    for(i = 1; i <= n; ++i)
        for(j = 1; j <= n; ++j)
            if(i != j && square(a[i], a[j]))
                sol++;
    fout << sol/4;
    ///va fi numarat de 4 ori pt ca face pt fiecare latura
    return 0;
}