.  #                
   o. #.    ∆          
   ... .   ∆          .
   ....#.           #..
   ......#######.. ...#
   .................!.o
##..######..#####......
.......<..†....†oK.#   
...########....##l.#   
          #..###  ..#  
          #..#     .#  
         #....      .# 
         #.##.#      ..
         #. ∆..       .
         ..  S..