% nurikabe 167 by ooya, http://www.janko.at/Raetsel/Nurikabe/167.a.htm
nurikabe
medium-
18 10
......6..........1
.........5.....4..
3....2....b.......
..4..........2....
...2...........4..
..................
..................
.2...............5
..4...3......5....
.....6....3...b...
