#include <bits/stdc++.h>

using namespace std;
using ll = long long;

void solve() {
    int n, k; cin >> n >> k;
    vector<vector<int>> ans;
    for (int round = 1; round <= k; ++round) {
        vector<int> cround(n);
        for (int i = 0; i < n; ++i) cround[i] = i ^ round;
        ans.push_back(cround);
        if (any_of(begin(cround), end(cround), [=] (int i) {return i >= n;})) {
            cout << "Impossible\n";
            return;
        }
    }
    for (auto &round : ans) {
        for (int i = 0; i < n; ++i) {
            cout << (i == 0 ? "" : " ") << round[i] + 1;
        }
        cout << "\n";
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t; cin >> t;
    while (t--) {
        solve();
    }
}