% nurikabe 600 by Toonkigou, http://www.janko.at/Raetsel/Nurikabe/600.a.htm
nurikabe
medium-
17 17
....5...3...2...4
.....4...........
..6.............5
.3...a...........
..............4..
.5..........2....
.....6.........2.
............3....
.6..3............
...............1.
3.....4...3......
...........1.4.2.
..............1..
3.3...2.6......3.
.................
.......3.........
4.......7..5....3
