#include <fstream>
#include <cmath>
#define NMax 1005
#include <set>
using namespace std;
ifstream fin("patrate3.in");
ofstream fout("patrate3.out");
set<pair <int, int>> coordinates; ///coordonatele punctelor
pair<int, int> a[NMax];


bool VerificPatrat(pair <int, int> a, pair<int, int> b)
{
    int x, y;
    y = b.first - a.first, x = a.second - b.second;
    if (coordinates.find({ a.first + x, a.second + y }) != coordinates.end())
        if(coordinates.find({ b.first + x, b.second + y }) != coordinates.end())     //cautam latura paralela 
        return 1;
    return 0;
}

int main()
{
    int i, j, N, rasp = 0;
    double x, y;
    fin >> N;
    for (i = 1; i <= N; ++i)
    {
        fin >> x >> y;
        x *= 10000, y *= 10000;
        a[i].first = round(x), a[i].second = round(y);
        coordinates.insert(a[i]); 
    }
    for (i = 1; i <= N; ++i)
        for (j = 1; j <= N; ++j)
            if (i != j && VerificPatrat(a[i], a[j]))     ///va fi numarat de 4 ori pt ca face pt fiecare latura
                rasp++;
    fout << rasp / 4;
    return 0;
}