. .##......#.# 
   #  # ...##..#  
      #..#. #.##  
 #. # .#..#..#.   
 ..#.#.### .###.. 
  #.####.##∩...#  
..##.......#...#  
 ....# .....#.#.# 
    #......###  . 
    #.#.###..#    
    #....#####    
    #....##.4##   
  #..#...#..#.#   
  ###.#....#.##   
   ..###..###.#   
  ..# #.#.#  ...  
 #.# #.##..   #.. 
 #. ..# ..#.   .##
 . ...  #.##.   # 
  #..   ..#       
  ##    #..