% nurikabe 427 by Otto Janko, http://www.janko.at/Raetsel/Nurikabe/427.a.htm
nurikabe
medium-
13 13
..2..2....3..
.........3...
...4........2
....1..3.....
4.........3..
.1.....1.....
.....4......4
2.....2......
...2.....4..2
4.1...3......
...3........2
.........1...
..2..3....3..
