--------------------------
|         -----          |
|    $    |              |
|         -----          |
|                        |
|          &    |        |
|                        |
|     $     ^    ~       |
|                        |
|                 4      |
|                        |
|      $         3       |
|                        |
|                        |
|       $       2        |
|                        |
--------------------------

# comment lines start with #
# walls/boundary: | -
# coins: $
# portal: digits