% slitherlink 570 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/570.a.htm
slitherlink
very hard
36 20
..1..1.1...31....33....13.....2..3..
.3..3.2..31....33..23....12..3.3..0.
1..2..0.2...03........12...3.1..0..3
.....1..0.1.....0..3.....1.1........
.333...1..3.1.31....33.1.2..2...122.
1....0.1.3.......30.......1.1.2....2
0....1...1.0.13.2..3.02.2.3...0....1
2.3.3.3....3............0....3.2.3.3
....1.0...2..2..2023..3..2...1.3....
.3.3....0...1..3....2..2...0....0.3.
.1.2....3...0..1....3..0...3....1.1.
....1.1...3..3..1132..3..3...1.0....
0.1.1.3....3............2....3.3.1.2
1....3...0.2.03.3..1.31.3.2...1....0
2....3.3.3.......13.......0.2.3....2
.310...3..2.3.23....02.3.2..2...132.
........0.3.....3..3.....0.2..3.....
0..3..2.2...31........20...0.1..3..1
.3..3.1..33....33..30....22..2.2..0.
..3..2.....31....21....02...2.0..3..
