% slitherlink 643 by Otto Janko, http://www.janko.at/Raetsel/Slitherlink/643.a.htm
slitherlink
medium-
19 10
.32......32...2....
12.3.3222312..3...2
.2212...2.2..1..312
2.....222322......2
321...13.2.12.1213.
23.211.2.232..2....
.2.2...22...222..2.
..2230...31.112221.
..1.3..212...12.232
3.3.313.2123...13..
