#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define int ll
#define vi vector<int>

const int INF = 1e18 + 5;

bool check(int n) {
    return n - (n & -n);
}


void solve()
{
    int n;
    cin >> n;
    if (n != 2 && !check(n)) {
        cout << "impossible\n";
        return;
    }

    vi a(n);
    for (int i=0; i<n; i++)
        a[i] = i;
    
    swap(a[0], a[1]);
    for (int i=4; i<n; i++) {
        if (!check(i)) {
            swap(a[i], a[i - 1]);
        }
    }

    for (int i=0; i<n; i++) 
        cout << a[i] << ' ';
    cout << '\n';
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    cin >> t;
    while (t--)
    {
        solve();
    }
}