.......... 
      ......... 
      .M.....#  
      .M....#   
      #....#    
∆     #....#    
∆∆    #....#    
∆     #....#    
∆     #....#    
∆∆∆   #....#    
∆∆    #....#   ∆
 ∆∆   #MM..#   ∆
 ∆∆   #.∩∩.#    
      ######