#include <bits/stdc++.h>
using namespace std;
//constant
const int MOD = 1e9 + 7;
//Shortcuts
#define ll long long
#define sz(x) (int)x.size()
#define pb push_back
#define lcm(a, b) (a * b != 0 ? a * b / __gcd(a, b) : 0)
#define f0(i, n) for (int i = 0; i < n; i++)
#define f1(i, n) for (int i = 1; i <= n; i++)
#define all(x) x.begin(), x.end()
#define sortall(x) sort(all(x))
#define debug(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
//Data Stucture
typedef array<int, 2> pi;
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef set<int> si;
typedef map<int, int> mpi;

void solve()
{
   ll l;cin>>l;
double k = sqrt(3);
cout<<k*l*l/36;
}

int main()
{
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    clock_t z = clock();
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t = 1;
    cin >> t;
    while (t--)
        solve();
    debug("Total Time: %.7f", (double)(clock() - z) / CLOCKS_PER_SEC);
    return 0;
}