.&.&.&...&                                          ..&..&&&..
......&...                                          &..&.&.&&.
.......&..                                          .&.....&&&
&.......&.                                          ..&....&.&
&&.......&                                          ...&.....&
.&&.......                                          ....&....&
.&&&......                                          &....&....
.&.&&.....                                          .&....&...
...&&&....                                          ..&....&..
...&.&&...                                          ...&....&.
.....&&&..                                          ....&....&