% nurikabe 590 by Adolfo Zanellati, http://www.janko.at/Raetsel/Nurikabe/590.a.htm
nurikabe
very hard
18 12
............3..3..
.....3...........1
..3.....3.1.1...3.
.............1....
.4...3..2..1......
.............1..3.
....2....2..3....2
..3...4.......1...
..................
...3......3..3..2.
..................
.4..3.2.2..3....3.
