% nurikabe 163 by ooya, http://www.janko.at/Raetsel/Nurikabe/163.a.htm
nurikabe
medium-
18 10
.....5.........b..
..................
.4.....5......4...
....3..........7..
...2.....4........
............2.....
...........8......
.......7.......4..
....6.......2....4
........4.3.......
