#include<bits/stdc++.h>
using namespace std;
const int N=2e6+5;
int n,a[N];
int main()
{
    int t;
    scanf("%d",&t);
    int k=1;
    for(int i=1;i<20;i++)
    a[k]=1,k*=2;
    while(t--)
    {
        scanf("%d",&n);
        //cout<<n<<endl;
        if(n==1)
        {
            printf("impossible\n");
            continue;
        }
        if(n==2)
        {
            printf("1 0\n");
            continue;
        }
        int m=n;
        while(m%2==0&&m)m/=2;
        if(m==1)
        {
            printf("impossible\n");
            continue;
        }
        printf("1 0");
        for(int i=2;i<n;i++)
        {
            if(a[i+1])
            printf(" %d %d",i+1,i),i++;
            else
            printf(" %d",i);
        }
        printf("\n");
    }
}