% slitherlink 644 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/644.a.htm
slitherlink
medium-
19 10
.32......322.1.....
2..322.........3122
2.222.21..1....31.2
.2....3.1223..1....
3...3..23..21..2233
2220.122.13.22.2...
..3.31..3.1.22.2.2.
3..022....2..1312..
3.3...3.3.1...2..32
...3.3.2.3.3....3..
