14 ++--------+---------+---------+---------+---------+---------+--------++
      +         +         +         +         +         +         +         +
      |                                                       %%%%%%%%%     |
      |                                             %%%%%%%%% %       %     |
   12 ++                                            %       % %       %    ++
      |                                             %       % %       %     |
      |     %%%%%%%%% %%%%%%%%%                     %       % $$$$$$$$$     |
      |     %       % %       %                     %       % $       $     |
   10 ++    $$$$$$$$$ %       %                     $$$$$$$$$ $       $    ++
      |     $       $ $$$$$$$$$                     $       $ $       $     |
      |     $       $ #########                     $       $ #########     |
      |     $       $ *********           %%%%%%%%% $       $ #       #     |
    8 ++    $       $ *       * %%%%%%%%% %       % $       $ #       #    ++
      |     $       $ *       * ######### $$$$$$$$$ ######### #       #     |
      |     ######### *       * #       # $       $ #       # #       #     |
      |     #       # *       * #       # ######### #       # #       #     |
    6 ++    #       # *       * #       # #       # #       # #       #    ++
      |     #       # *       * #       # #       # #       # #       #     |
      |     ********* *       * #       # #       # ********* #       #     |
      |     *       * *       * ********* #       # *       * *********     |
    4 ++    *       * *       * *       * ********* *       * *       *    ++
      |     *       * *       * *       * *       * *       * *       *     |
      |     *       * *       * *       * *       * *       * *       *     |
      |     *       * *       * *       * *       * *       * *       *     |
    2 ++    *       * *       * *       * *       * *       * *       *    ++
      |     *       * *       * *       * *       * *       * *       *     |
      |     *       * *       * *       * *       * *       * *       *     |
      +     *   +   * *   +   * *   +   * *   +   * *   +   * *   +   *     +
    0 ++----*********-*********-*********-*********-*********-*********----++
     -1         0         1         2         3         4         5         6