#include <bits/stdc++.h>

using namespace std;

void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}
using Point = pair<long long, long long>;
Point calc(Point p1, Point p2, Point p3) {
    long long dx1 = p2.first - p1.first;
    long long dy1 = p2.second - p1.second;
    long long dx2 = p3.first - p1.first;
    long long dy2 = p3.second - p1.second;
    return {p1.first + dx1 + dx2, p1.second + dy1 + dy2};
}
long long dist(Point p1, Point p2) {
    long long dx = p1.first - p2.first;
    long long dy = p1.second - p2.second;
    return dx * dx + dy * dy;
}
int main() {
    fast_io();
    int n;
    cin >> n;
    vector<Point> xy(n);
    for (long long i = 0; i < n; i++) {
        cin >> xy[i].first >> xy[i].second;
    }
    set<Point> st(xy.begin(), xy.end());
    long long ans = 0;
    for (long long i = 0; i < n; i++) {
        auto [x1, y1] = xy[i];
        for (long long j = i + 1; j < n; j++) {
            auto [x2, y2] = xy[j];
            for (long long k = j + 1; k < n; k++) {
                auto [x3, y3] = xy[k];
                auto p1 = xy[i];
                auto p2 = xy[j];
                auto p3 = xy[k];
                auto p4 = calc({x1, y1}, {x2, y2}, {x3, y3});
                if (dist(p2, p1) == dist(p3, p1) && st.count(p4) && p4 != p1) {
                    ans++;
                }
                auto p5 = calc({x2, y2}, {x1, y1}, {x3, y3});
                if (dist(p1, p2) == dist(p2, p3) && st.count(p5) && p5 != p2) {
                    ans++;
                }
                auto p6 = calc({x3, y3}, {x1, y1}, {x2, y2});
                if (dist(p1, p3) == dist(p2, p3) && st.count(p6) && p6 != p3) {
                    ans++;
                }
            }
        }
    }
    cout << ans / 4 << endl;
}