. .. # .. ... # .. .# ..# # #.#..# ###...# ... #._...#.## ∆ # ...# ... .#.#. .#.. ##.#. .. ... . # .. #...# . #. .#... ######## #.#.#... ......# # . .. . # .# ....≈.# ... ##. # #≈#####≈.###.. . . # ≈ . #...#≈∩.≈.# #≈# . #.(.#≈##≈≈# ≈ . .## #vv.#...≈≈≈# .# #.#'v'#.#≈.≈#≈≈ .# #..v..###### ≈# +.....'.v.# ≈ ∆ +..8..vvv.# +.....'.v.# #.....##### #.#+++#. ... ## ##