source_code: import java.util.*;
  import java.io.*;
  public class Main {
     
   
        static class Reader {
          final private int BUFFER_SIZE = 1 << 16;
          private DataInputStream din;
          private byte[] buffer;
          private int bufferPointer, bytesRead;
   
          public Reader()
          {
              din = new DataInputStream(System.in);
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
   
          public Reader(String file_name) throws IOException
          {
              din = new DataInputStream(
                  new FileInputStream(file_name));
              buffer = new byte[BUFFER_SIZE];
              bufferPointer = bytesRead = 0;
          }
   
          public String readLine() throws IOException
          {
              byte[] buf = new byte[64]; // line length
              int cnt = 0, c;
              while ((c = read()) != -1) {
                  if (c == '\n') {
                      if (cnt != 0) {
                          break;
                      }
                      else {
                          continue;
                      }
                  }
                  buf[cnt++] = (byte)c;
              }
              return new String(buf, 0, cnt);
          }
   
          public int nextInt() throws IOException
          {
              int ret = 0;
              byte c = read();
              while (c <= ' ') {
                  c = read();
              }
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
   
              if (neg)
                  return -ret;
              return ret;
          }
   
          public long nextLong() throws IOException
          {
              long ret = 0;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
              if (neg)
                  return -ret;
              return ret;
          }
   
          public double nextDouble() throws IOException
          {
              double ret = 0, div = 1;
              byte c = read();
              while (c <= ' ')
                  c = read();
              boolean neg = (c == '-');
              if (neg)
                  c = read();
   
              do {
                  ret = ret * 10 + c - '0';
              } while ((c = read()) >= '0' && c <= '9');
   
              if (c == '.') {
                  while ((c = read()) >= '0' && c <= '9') {
                      ret += (c - '0') / (div *= 10);
                  }
              }
   
              if (neg)
                  return -ret;
              return ret;
          }
   
          private void fillBuffer() throws IOException
          {
              bytesRead = din.read(buffer, bufferPointer = 0,
                                   BUFFER_SIZE);
              if (bytesRead == -1)
                  buffer[0] = -1;
          }
   
          private byte read() throws IOException
          {
              if (bufferPointer == bytesRead)
                  fillBuffer();
              return buffer[bufferPointer++];
          }
   
          public void close() throws IOException
          {
              if (din == null)
                  return;
              din.close();
          }
      }
       //System.out.println("YES");
  //System.out.println("NO");
   
  //int n=sc.nextInt();
  //int a[]=new int[n];
  //for(int i=0;i<n;i++)
  //a[i]=sc.nextInt();
   
  //int n=sc.nextInt();
  //long a[]=new long[n];
  //for(int i=0;i<n;i++)
  //a[i]=sc.nextLong();
   
  //System.out.println();
   
  //String str=sc.next();
  //long n=sc.nextLong();
  
    
      public static void main(String[] args) throws IOException{
          Scanner sc=new Scanner(System.in);
        //  Reader sc=new Reader();
          PrintWriter out=new PrintWriter(System.out);
          int t = sc.nextInt();
  		while(t-->0) {
  		    int n=sc.nextInt();
  		     ArrayList<Integer> al[]=new ArrayList[n+1];
  		     
  		    for(int i=0;i<=n;i++)
  		    al[i]=new ArrayList<>();
  		    
  		    al[0].add(1);
  		    
  		    int y;
  		    y=sc.nextInt();
  		    boolean flag=true;
  		    for(int i=1;i<=n-1;i++) {
  		         int x=sc.nextInt();
  		        int idx=al[i-1].size()-1;
  		        if(x!=1) {
  		            while(flag) {
  		                int ans=x-1;
  		                if(al[i-1].get(idx)==ans) {
  		                    idx--;
  		                   break;
  		                }
  		                idx--;
  		            }
  		        }
  		        for(int j=0;j<=idx;j++) {
  		            al[i].add(al[i-1].get(j));
  		        }
  		        al[i].add(x);
  		    }
  		    
  		    for(int i=0;i<=n-1;i++) {
  		        out.print(al[i].get(0));
  		        for(int j=1;j<=al[i].size()-1;j++) {
  		            out.print("."+al[i].get(j));
  		        }
  		        out.println();
  		    }
  	
          
    }
  		  
  		  out.flush();
  		  out.close();
  		 
  		  
    
  		  
          }
          
  		
  	
  }
  