% slitherlink 183 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/183.a.htm
slitherlink
very hard
30 20
..2.3..2....2.23.322....3...23
.3....3.13.3.2.22.12.33.32....
31.......2.2.123.....11...03.2
..311..3...223.1...0...2....22
.....3..2.2...322.3..1212.....
233..0....22......2.2.2.2..3.3
...2...1.20.3....2.3.2...1.2..
..23..2.2.2...3..2.0.1..12..3.
1....02..3.3..2.1..2...3...2.3
.212.....3..2.13.31..2222..011
3.32.2.122..2...1.3......3....
322..3221...3.33.1...1..2.....
2.3.12.3.1.21......3..1..2....
.3.....12....1320.....23..3.2.
...1..22..11....2.22....2.132.
.2.13.2.3..322.3.32..2.3.2022.
....3.2.11.1..1..3..3.2..2...2
3....22.222..1.322..11..3..212
.....232.....2..2213.312.12...
.2.3.121..3.31.3.......2.33...
