/*CODED BY mahmudulsakib2019
  DATE:-06/3/2024;TIME:-07:39 pm
  BANGALDESH , SYLHET*/

#include <iostream>
#include <cmath>     ///mathematics
#include <vector>    ///array
#include <regex>     ///searching_prefix_suffix
#include <algorithm> ///finding_max_min_from_array
#include <string>    ///string_manipulation
#include <numeric>   ///findin total sum of an array
using namespace std;

int main() {
    int T;
    cin >> T;
    while (T--) {
        int B;
        cin >> B;
        if (B <= 2) {
            cout << -1 << endl;
        } else if (B % 2 == 0) {
            int side = B / 2;
            int perimeter = 2 * (side * side + B);
            cout << perimeter << endl;
        } else {
            int side = B / 2;
            int perimeter = 2 * (side * (side + 1));
            cout << perimeter << endl;
        }
    }
    return 0;
}