#include<bits/stdc++.h>
#define rep(i,l,r) for(int i=l;i<=r;i++)
using namespace std;
const int N = 1005;
int T;
int n, k;
int a[N];
int ans[N];
void work(){
    scanf("%d%d", &n, &k);
    if (n%4 || k >= n) {
        printf("Impossible\n");
        return;
    }
    rep(i, 1, n) {
        printf("%d ", i&1 ? i+1 : i-1);
    }
    printf("\n");
    if(--k==0) return;
    int x = n/4;
    rep(i, 0, x*2-1) a[i]=i;
    rep(t, 1, x*2-1) {
        rep(i, 0, x*2-2) {
            a[i]=(a[i]+1)%(x*2-1);
        }
        rep(i, 0, x-1) {
            int l=a[i], r=a[x*2-1-i];
            ans[l*2]=r*2;
            ans[r*2]=l*2;
            ans[l*2+1]=r*2+1;
            ans[r*2+1]=l*2+1;
        } 
        rep(i,0,n-1) {
            printf("%d ", ans[i]+1);
        }
        printf("\n");
        if(--k==0) return;
        rep(i, 0, x-1) {
            int l=a[i], r=a[x*2-1-i];
            ans[l*2]=r*2+1;
            ans[r*2]=l*2+1;
            ans[l*2+1]=r*2;
            ans[r*2+1]=l*2;
        } 
        rep(i,0,n-1) {
            printf("%d ", ans[i]+1);
        }
        printf("\n");
        if(--k==0) return;
    }
    
}
int main(){
    scanf("%d", &T);
    while(T--){
        work();
    }
    return 0;
}