#include<iostream>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<string>
#include<cstdlib>
#include<iomanip>
#include<queue>
#include<vector>
#include<bitset>
#include<set>
#include<stack>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
const int maxn=1e6+5;
inline int read()
{
	int x=0,y=1; char c=getchar();
	while(c<'0'||c>'9') {if(c=='-') y=-1; c=getchar();}
	while(c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
	return x*y;
}
int n,T;
bool st[maxn];
int ans[maxn];
int main()
{
	for(int base=2;base<=maxn;base<<=1) st[base-1]=1;
	T=read();
	while(T--)
	{
		n=read();
		if(n==1||n%4==0) {printf("impossible\n"); continue;}
		ans[0]=1; ans[1]=0; ans[2]=2;
		for(int i=3;i<n;i++)
		{
			if(i&&st[i-1]) continue;
			if(st[i]) ans[i]=i+1,ans[i+1]=i;
			else ans[i]=i;
		}
		for(int i=0;i<n;i++) printf("%d ",ans[i]),ans[i]=i;
		puts("");
	}
	return 0;
}