% slitherlink 640 by Luke Pebody, http://www.janko.at/Raetsel/Slitherlink/640.a.htm
slitherlink
hard-
19 16
.3232...3.32...2.32
..22.32..3.1223..1.
3.32.3...22..213...
....23.3....3...1..
2232221.22.2..1....
.2.22.......1.213..
3.2...331.2.2.2....
2.1..3...3.13.1....
.2....2.......3...3
23..23.1.322.......
1231..10....3.212.1
...1...12.213.2.232
21....1222.....2...
..3.2.....2.3..122.
.1.323.22...13.2.31
.3.......3.3......3
