#include <iostream>
#include <vector>
#include <set>
#define LL long long

#define M 2005
#define P 1000

using namespace std;

bool in_bounds(int x) {
    return x >= 0 && x < M;
}

int main()
{
    vector<vector<bool> > m(M, vector<bool>(M, false));
    int N;
    cin >> N;
    vector<int> xs(N), ys(N);
    int x, y;
    for (int i = 0; i < N; ++i) {
        cin >> x >> y;
        x = x + P;
        y = y + P;
        xs[i] = x;
        ys[i] = y;
        m[x][y] = true;
    }
    set<pair<int,int>> deltas;
    int out = 0;
    for (int i = 0; i < N - 1; ++i) {
        int dx = xs[i] - x,
            dy = ys[i] - y;

        //cout << dx << " " << dy << endl;
        bool ok = true;
        for (int j = 0; j < N; ++j) {
            if (in_bounds(xs[j] + dx) && in_bounds(ys[j] + dy) && m[xs[j] + dx][ys[j] + dy]) {
                continue;
            }
            if (in_bounds(xs[j] - dx) && in_bounds(ys[j] - dy) && m[xs[j] - dx][ys[j] - dy]) {
                continue;
            }
            ok = false;
            break;
        }
        if (ok && (deltas.find({dx, dy}) == deltas.end())) {
            out++;
            deltas.insert({dx, dy});
            deltas.insert({-dx, -dy});
        }
    }
    cout << 2 * out << endl;
    return 0;
}