#include <bits/stdc++.h>

using namespace std;

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

vector<pair<int,int>> pct;
set<pair<int,int>> mult;

int main()
{
    int n;
    double x,y;

    fin>>n;
    for (int i=0; i<n; i++) {
        fin>>x>>y;
        pct.push_back(make_pair((int)round(x*10000), (int)round(y*10000)));
        mult.insert(pct[i]);
    }

    sort(pct.begin(), pct.end());

    int nr=0;
    for (int i=0; i<n-1; i++) {
        for (int j=i+1; j<n; j++) {
            if (pct[i].second < pct[j].second) {
                int distx = pct[j].first - pct[i].first;
                int disty = pct[j].second - pct[i].second;

                pair<int,int> pct3, pct4;
                pct3 = make_pair(pct[i].first - disty, pct[i].second + distx);
                pct4 = make_pair(pct[j].first - disty, pct[j].second + distx);

                if (mult.find(pct3) != mult.end() &&
                    mult.find(pct4) != mult.end())
                        nr++;

            }
        }
    }

    fout<<nr;

    fin.close();
    fout.close();
    return 0;
}