....##....##..   
  ..............  
   .............  
    ...........   
     ........#    
      ......#     
      #....#      
∆     #....#     ∆
∆∆    #....#     ∆
∆     #....#     ∆
∆∆    #....#    ∆∆
∆∆    #....#   ∆ ∆
∆∆    #.ZZZ#    ∆∆
 ∆∆   #.ZMM#   ∆∆ 
 ∆∆   #.ZM.#    ∆ 
      ######