source_code: import java.util.StringTokenizer;
  import java.io.InputStreamReader;
  import java.lang.reflect.Array;
  import java.io.IOException;
  import java.io.BufferedReader;
  import java.math.BigInteger;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.ArrayList;
  
  public class p3
  {
  	static class FastReader {
  		BufferedReader br;
  		StringTokenizer st;
  
  		public FastReader()
  		{
  				br = new BufferedReader(new InputStreamReader(System.in));
  		}
  
  		String next()
  		{
  				while (st == null || !st.hasMoreElements()) {
  						try {
  								st = new StringTokenizer(br.readLine());
  						}
  						catch (IOException e) {
  								e.printStackTrace();
  						}
  				}
  				return st.nextToken();
  		}
  
  		int nextInt() { return Integer.parseInt(next()); }
  
  		byte nextByte() { return Byte.parseByte(next()); }
  
  		short nextShort() { return Short.parseShort(next()); }
  
  		long nextLong() { return Long.parseLong(next()); }
  
  		double nextDouble()	{	return Double.parseDouble(next());	}
  
  		String nextLine()
  		{
  				String str = "";
  				try {
  						str = br.readLine();
  				}
  				catch (IOException e) {
  						e.printStackTrace();
  				}
  				return str;
  		}
  	}
  
  	public static void main(String[] args)
  	{
  		FastReader fr=new FastReader();
  
  		byte t=fr.nextByte();
  		while(t-->0)
  		{
  			short n=fr.nextShort();
  			short a[]=new short [n];
  			for (short i=-1;++i<n;)
  				a[i]=fr.nextShort();
  			
  			String s="1";
  			System.out.println(s);
  
  			for(short i=0;++i<n;)
  			{
  				if(a[i]==1)
  				{
  					s+=".1";
  					System.out.println(s);
  				}
  				else if(a[i]==a[i-1]+1)
  				{
  					int c=s.lastIndexOf(".");
  					s=s.substring(0,c+1)+a[i];
  					System.out.println(s);
  				}
  				else
  				{					
  					for(;;)
  					{
  						s=s.substring(0,s.lastIndexOf("."));
  						int c=s.lastIndexOf(".");
  
  						int b=Integer.parseInt(s.substring(c+1,s.length()));
  						if(b+1==a[i])
  						{
  							s=s.substring(0,c+1)+a[i];
  							System.out.println(s);
  							break;
  						}
  					}
  				}
  			}
  		}
  	}
  }