source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.InputMismatchException;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   *
   * @author dauom
   */
  public class Main {
    public static void main(String[] args) {
      InputStream inputStream = System.in;
      OutputStream outputStream = System.out;
      InputReader in = new InputReader(inputStream);
      PrintWriter out = new PrintWriter(outputStream);
      CCompressionAndExpansion solver = new CCompressionAndExpansion();
      int testCount = Integer.parseInt(in.next());
      for (int i = 1; i <= testCount; i++)
        solver.solve(i, in, out);
      out.close();
    }
  
    static class CCompressionAndExpansion {
      public final void solve(int testNumber, InputReader in, PrintWriter out) {
        int n = in.nextInt();
  
        ArrayList<ArrayList<Integer>> ans = new ArrayList<>();
        ArrayList<Integer> start = new ArrayList<>();
        start.add(in.nextInt());
        ans.add(start);
        out.println("1");
        for (int i = 1; i < n; i++) {
          ArrayList<Integer> lastList = ans.get(ans.size() - 1);
          ArrayList<Integer> curList = (ArrayList<Integer>) lastList.clone();
          ans.add(curList);
  
          int curLast = in.nextInt();
          for (int j = lastList.size() - 1; j >= 0; j--) {
            int last = lastList.get(j);
            if (curLast == 1) {
              curList.add(1);
              break;
            } else if (curLast == last + 1) {
              curList.set(j, curLast);
              break;
            } else {
              curList.remove(j);
            }
          }
          for (int j = 0; j < curList.size(); j++) {
            if (j > 0) out.print(".");
            out.print(curList.get(j));
          }
          out.println();
        }
      }
  
    }
  
    static final class InputReader {
      private final InputStream stream;
      private final byte[] buf = new byte[1 << 18];
      private int curChar;
      private int numChars;
  
      public InputReader() {
        this.stream = System.in;
      }
  
      public InputReader(final InputStream stream) {
        this.stream = stream;
      }
  
      private int read() {
        if (this.numChars == -1) {
          throw new UnknownError();
        } else {
          if (this.curChar >= this.numChars) {
            this.curChar = 0;
  
            try {
              this.numChars = this.stream.read(this.buf);
            } catch (IOException ex) {
              throw new InputMismatchException();
            }
  
            if (this.numChars <= 0) {
              return -1;
            }
          }
  
          return this.buf[this.curChar++];
        }
      }
  
      public final int nextInt() {
        int c;
        for (c = this.read(); isSpaceChar(c); c = this.read()) {
        }
  
        byte sgn = 1;
        if (c == 45) { // 45 == '-'
          sgn = -1;
          c = this.read();
        }
  
        int res = 0;
  
        while (c >= 48 && c <= 57) { // 48 == '0', 57 == '9'
          res *= 10;
          res += c - 48; // 48 == '0'
          c = this.read();
          if (isSpaceChar(c)) {
            return res * sgn;
          }
        }
  
        throw new InputMismatchException();
      }
  
      public final String next() {
        int c;
        while (isSpaceChar(c = this.read())) {
        }
  
        StringBuilder result = new StringBuilder();
        result.appendCodePoint(c);
  
        while (!isSpaceChar(c = this.read())) {
          result.appendCodePoint(c);
        }
  
        return result.toString();
      }
  
      private static boolean isSpaceChar(final int c) {
        return c == 32 || c == 10 || c == 13 || c == 9
            || c == -1; // 32 == ' ', 10 == '\n', 13 == '\r', 9 == '\t'
      }
  
    }
  }
  
  