source_code: import java.util.*;
  import java.io.*;
  
  public class C {
      public static void main(String[] args) throws IOException{
          BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
          PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
          int t = Integer.parseInt(f.readLine());
          while(t-->0){
              int n = Integer.parseInt(f.readLine());
              int[] arr = new int[n];
              for(int i = 0; i < n; i++){
                  arr[i] = Integer.parseInt(f.readLine());
              }
              int[] levels = new int[n];
              int curr_level = 0;
              for(int i = 0; i < n; i++){
                  if(levels[curr_level] == arr[i]-1){
                      levels[curr_level]++;
                  }else if(arr[i] == 1){
                      curr_level++;
                      levels[curr_level]++;
                  }else if(arr[i] > 1){
                      while(curr_level > 0 && levels[curr_level] != arr[i]-1){
                          levels[curr_level] = 0;
                          curr_level--;
                      }
                      levels[curr_level]++;
                  }
                  StringBuilder ostring = new StringBuilder();
                  for(int level = 0; level <= curr_level; level++){
                      ostring.append(levels[level]);
                      if(level != curr_level) ostring.append(".");
                  }
                  out.println(ostring);
              }
  
          }
          out.close();
      }
  }
  