% slitherlink 645 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/645.a.htm
slitherlink
medium
17 17
..12233....23221.
.32...1...2..22..
..21.23....2232..
.222.022.031.11.1
...122..22.2..22.
...23...3.22.312.
.23...1.1..1.2.3.
..2.2.232..132...
22....1.12...2.22
3.311.2.32..1..22
.12.21...1.23..3.
.222.221.2.12..02
.1122.2123..222..
.22..1...2...1122
.222.2...32212..2
.32.1...11.22...2
..23233...3.323..
