//Thomas Meeks 6/7/2023
//Refactored program "MakeX" from 6/6/2023 to make use of a "Solve" function for cleaner code;
#include <iostream>
using namespace std;
void printX(int dim){
    for(int row = 0; row < dim; row++){
      for(int col = 0; col < dim; col++){
        if(row==col || row+col == (dim-1)) cout << "#";
        else cout << " ";
      }
      cout << '\n';
    }
}

int main(){
  int cases; cin >> cases;
  int caseNumber = 1;
  while(cases--){
    int dim; cin >> dim;
    cout << "Case : " << caseNumber++ << "\n";
    printX(dim);
  }
  return 0;
}