#include <bits/stdc++.h>
#define rep(i, a, b) for (auto cc##i = (b), i = (a); i <= cc##i; ++i)
#define per(i, a, b) for (auto cc##i = (b), i = (a); i >= cc##i; --i)
#define debug(...) fprintf(stderr, __VA_ARGS__)
using namespace std;

const int N = 1e3 + 5;

int n, k;

void solve() {
  cin >> n >> k;
  vector<vector<int>> ans;
  rep(tt, 1, k) {
    vector<int> a(n);
    for (int i = 0; i < n; ++i) {
      int j = i ^ tt;
      if (j >= n) {
        cout << "Impossible\n";
        return;
      }
      a[i] = j;
    }
    ans.push_back(a);
  }
  for (auto &a : ans) {
    rep(i, 0, n - 1) cout << a[i] + 1 << " \n"[i == n - 1];
  }
}

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int t;
  cin >> t;
  while (t--) solve();
  return 0;
}