% slitherlink 336 by Hirofumi Fujiwara, http://www.janko.at/Raetsel/Slitherlink/336.a.htm
slitherlink
very hard
20 16
2..1.2..3..3.31.13.1
3...3.1..3.3.3......
.1.0.2.13....1..3103
.1....3...0.1.3.....
3...12...1..1..21..1
.32.3..0.3.3.0.13...
1...3.....1...3..113
3...1.13..31..1.1...
.31..31.01..11....1.
...1.......1...01112
2.1....3..1.20...3.3
21.3.110.0...11..1..
1..3.....3.1....311.
1.3.0........1....13
...1..202.33...1.1.3
2.....3...1.31.3..3.
