#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    int n;
    cin >> n;
    vector<unordered_map<ll,bitset<1000>>> r(n);
    vector<ll> x(n), y(n);
    rep(i,n) {
        cin >> x[i] >> y[i];
    }
    rep(i,n)rep(j,n) {
        if(i==j) continue;
        ll dist = (x[i]-x[j])*(x[i]-x[j]) + (y[i]-y[j])*(y[i]-y[j]);
        r[i][dist][j] = 1;
    }
    ll ans = 0;
    rep(i,n)rep(j,n) {
        if(i==j) continue;
        for(auto p : r[i]) {
            if(!r[j].count(p.first)) continue;
            int val = (p.second&r[j][p.first]).count();
            ans += val*(val-1)/2;
        }
    }
    cout << ans/4 << endl;
    return 0;
}