% slitherlink 521 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/521.a.htm
slitherlink
easy+
10 10
.2..21..2.
30.3..0.31
..........
.3..03..2.
3..3..0..2
1..3..3..0
.3..20..1.
..........
12.3..3.30
.3..21..3.
