#include <bits/stdc++.h>

using namespace std;
#define IOS ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)
#define rep(a, b, c) for(int (a)=(b);(a)<=(c);(a)++)
#define per(a, b, c) for(int (a)=(b);(a)>=(c);(a)--)
#define mset(var, val) memset(var,val,sizeof(var))
#define ll long long
#define int ll
#define fi first
#define se second
#define pb push_back
// #define endl "\n"
#define pii pair<int,int>
#define pll pair<ll,ll>
#define dbg(x...) do{cout<<#x<<" -> ";err(x);}while (0)

void err() { cout << '\n'; }

template<class T, class... Ts>
void err(T arg, Ts... args) {
    cout << arg << ' ';
    err(args...);
}

const int N = 1e6+5;

int n;

void solve() {
    cin >> n;
    if(n%3 == 0) {
        cout << (n/3)*(n/3)*(n/3) << endl;
        return;
    }
    if(n%4 == 0) {
        cout << (n/4)*(n/4)*(n/2) << endl;
        return;
    }
    cout << "-1" << endl;
}

signed main() {
    IOS;
    int T = 1;
    cin >> T;
    while (T--) {
        solve();
    }
    return 0;
}