1 #include <iostream>
 2 #include <stdio.h>
 3 #include <math.h>
 4 #include <string.h>
 5 #include <stdlib.h>
 6 #include <string>
 7 #include <vector>
 8 #include <set>
 9 #include <map>
10 #include <queue>
11 #include <algorithm>
12 #include <sstream>
13 #include <stack>
14 using namespace std;
15 #define rep(i,a,n) for (int i=a;i<n;i++)
16 #define per(i,a,n) for (int i=n-1;i>=a;i--)
17 #define pb push_back
18 #define mp make_pair
19 #define all(x) (x).begin(),(x).end()
20 #define fi first
21 #define se second
22 #define SZ(x) ((int)(x).size())
23 #define FO freopen("in.txt", "r", stdin)
24 #define lowbit(x) (x&-x)
25 #define mem(a,b) memset(a, b, sizeof(a))
26 typedef vector<int> VI;
27 typedef long long ll;
28 typedef pair<int,int> PII;
29 const ll mod=1000000007;
30 const int inf = 0x3f3f3f3f;
31 ll powmod(ll a,ll b) {ll res=1;a%=mod;for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
32 ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
33 //head
34 
35 int _, n;
36 int main() {
37     for(scanf("%d", &_);_;_--) {
38         scanf("%d", &n);
39         if(n%3 == 0) printf("%lld\n", 1ll * n * n * n / 27);
40         else if(n%4 == 0) printf("%lld\n", 1ll * n * n * n / 32);
41         else puts("-1");
42     }
43 }