% slitherlink 509 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/509.a.htm
slitherlink
hard-
24 14
....2.1.3.3....223.3.333
3.3....3..132.........22
.12..3......121.3.3..3.2
.22.2..12022....21212..2
13.3..1..22..3..22..32..
.......3121..31.......1.
..12322.......2...11.213
.213.113...23...3..3..3.
.3..323......3.32.21...1
..2..0.2....12.22...2223
2222..22112233......1.1.
.....3....221..02...2...
23..12223...22.2..23.203
3.1...2122.232...222....
