.    .       
      #..### .. .    
    .......# .....   
   #.......# .....#  
 ..#.......##.....#  
.#.#.#.#.#.#.#.#.#   
.................    
##.#.#.#.#.#.#.#.#.#.
#?.......a...a.......
 #.#.#.#.#.#<#.#.#.#.
 #...b...###b......# 
 #.##a##.# #.......# 
    #.##.# #........ 
    #............... 
    ####.###.......  
       ..# #......   
       ### #.....    
           ###