#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e6 + 10;
int a[N];
void solve()
{
    int n;
    cin >> n;
    if (n % 4 == 0)
    {
        cout << "impossible" << endl;
        return;
    }

    for (int i = 0; i < n; i++)
    {
        a[i] = i;
    }
    a[0] = 1;
    a[1] = 0;
    int t = 4;
    while (t < n)
    {
        a[t] = t - 1;
        a[t - 1] = t;
        t += 4;
    }
    for (int i = 0; i < n; i++)
        cout << a[i] << " ";
    cout << endl;
}

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