% slitherlink 523 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/523.a.htm
slitherlink
medium-
18 10
13.1.23.11.23.0.22
13.....0..2.....02
...102.1132.323...
..................
02.21..3.13.03..31
23..03.31.1..20.30
..................
...331.3101.013...
30.....3..3.....33
23.0.13.22.23.0.01
