% nurikabe 550 by Adolfo Zanellati, http://www.janko.at/Raetsel/Nurikabe/550.a.htm
nurikabe
hard-
16 12
..2.2.....2.....
......2.......6.
...6.......4.5..
....2...........
......2...2.....
..............2.
3..2..3.4..4....
.2.......2.....2
........2.......
..3......3...1..
3.......1.......
.....5....1.2..3
