% kuromasu 20 by Warai Kamosika, http://www.janko.at/Raetsel/Kuromasu/020.a.htm
kuromasu
hard
17 17
..............2..
.4.....2.....8...
3..4....8.9......
.....6.....a.8.2.
..6.2.....a......
......4.....4....
.2.....c.a...2..7
4.a.....5......3.
....e.8...b.6....
.6......a.....2.2
3..6...g.e.....2.
....c.....9......
......3.....9.8..
.3.5.a.....a.....
......7.7....4..3
...8.....8.....3.
..a..............
