#include <bits/stdc++.h>
using namespace std;
using ll = long long;

void solve() {
  int n,k;
  cin >> n >> k;
  if (n%2 == 1) {
    cout << "Impossible" << "\n";
    return;
  }
  vector g(n, vector<int>(n));
  for (int i=0;i<n;i++){
    g[i][i] = true;
  }
  vector<vector<int>> ans;
  for (int i=0;i<k;i++){
    ans.push_back(vector<int>(n));
    bool ok = true;
    vector<int> vis(n);
    set<int> todo;
    for (int j=0;j<n;j++) todo.insert(j);
    while (!todo.empty()) {
      int cur = *todo.begin();
      todo.erase(todo.begin());
      int next = -1;
      for (int j=0;j<n;j++){
        if (cur != j && !g[cur][j] && !vis[j]) {
          next = j;
          break;
        }
      }
      if (next == -1) {
        ok = false;
        break;
      }
      auto dfs = [&] (auto self, int u, int v) -> void {
        todo.erase(u);
        todo.erase(v);
        vis[u] = true;
        vis[v] = true;
        g[u][v] = true;
        g[v][u] = true;
        ans.back()[u] = v;
        ans.back()[v] = u;
        vector<int> left, right;
        for (int l=0;l<n;l++){
          if (l == u || vis[l] || g[u][l] || !g[v][l])
            continue;
          left.push_back(l);
        }
        for (int r=0+1;r<n;r++){
          if (r == v || vis[r] || g[v][r] || !g[u][r])
            continue;
          right.push_back(r);
        }
        for (int i=0;i<left.size();i++){
          self(self, left[i], right[i]);
        }
      };
      dfs(dfs, cur, next);
    }
    if (!ok) {
      cout << "Impossible" << "\n";
      return;
    }
  }
  for (int i=0;i<k;i++) {
    for (int j=0;j<n;j++) {
      if (j != n-1) {
        cout << ans[i][j] + 1 << " ";
      } else {
        cout << ans[i][j] + 1;
      }
    }
    cout << "\n";
  }
  
}

int main() {
  int t;
  cin >> t;
  while (t--)
    solve();
}