source_code: import java.util.*;
  import java.io.*;
  public class C {
  
  	public static void main(String[] args) {
  		FastScanner sc = new FastScanner();
  		int T = sc.nextInt();
  		StringBuilder sb = new StringBuilder();
  		while(T-->0) {
  			int n = sc.nextInt();
  			int[] arr = new int[n];
  			for(int i = 0; i < n; i++) {
  				arr[i] = sc.nextInt();
  			}
  			int[] p = new int[n];
  			int[] base = new int[n];
  			p[0] = -1;
  			base[0] = -1;
  			boolean[] used = new boolean[n];
  			for(int i = 1; i < n; i++) {
  				if(arr[i] == 1) {
  					p[i] = i-1;
  					base[i] = i-1;
  				}
  				else {
  					for(int j = i-1; j >= 0; j--) {
  						if(used[j]) continue;
  						if(arr[j] == arr[i]-1) {
  							p[i] = j; used[j] = true; 
  							base[i] = base[j]; break;
  						}
  						else used[j] = true;
  					}
  				}
  			}
  			StringBuilder[] res = new StringBuilder[n];
  			res[0] = new StringBuilder("1");
  			sb.append("1\n");
  			for(int i = 1; i < n; i++) {
  				if(base[i] == -1) { 
  					res[i] = new StringBuilder();
  				}
  				else {
  					res[i] = new StringBuilder(res[base[i]]);
  					res[i].append(".");
  				}
  				res[i].append(arr[i]+"");
  				sb.append(res[i]);
  				sb.append("\n");
  			}
  		}	
  		PrintWriter pw = new PrintWriter(System.out);
  		pw.println(sb.toString().trim());
  		pw.flush();
  	}
  	static class FastScanner {
  		public BufferedReader reader;
  		public StringTokenizer tokenizer;
  		public FastScanner() {
  			reader = new BufferedReader(new InputStreamReader(System.in), 32768);
  			tokenizer = null;
  		}
  		public String next() {
  			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
  				try {
  					tokenizer = new StringTokenizer(reader.readLine());
  				} catch (IOException e) {
  					throw new RuntimeException(e);
  				}
  			}
  			return tokenizer.nextToken();
  		}
  		public int nextInt() {
  			return Integer.parseInt(next());
  		}
  		public long nextLong() {
  			return Long.parseLong(next());
  		}
  		public double nextDouble() {
  			return Double.parseDouble(next());
  		}
  		public String nextLine() {
  			try {
  				return reader.readLine();
  			} catch(IOException e) {
  				throw new RuntimeException(e);
  			}
  		}
  	}
  
  }
  