% slitherlink 174 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/174.a.htm
slitherlink
hard-
20 15
...2222....3.3...1..
2.23.3.1.1.2...212.2
3..21.3.3.331..1..23
.3..3.31.111.2221222
...3..3......1..3..2
.1.23..11.2..3.12.2.
..3.2....1.10.3.2.23
........023201....3.
.1.1.133.21.2.2.1.21
32..3.....2.2.1.2..2
..2..3.......223....
.22.11..33...21.13.3
.....2..2..1....2..1
2.32..32..122.1.0..2
3.13.32.1....3.3.3..
