% heyawake 251 by Mokuani, http://www.janko.at/Raetsel/Heyawake/251.a.htm
heyawake
easy+
10 10
+---+-----+-----+---+
|2..|2....|2....|2..|
|...|.....|.....|...|
|...|.....|.....|...|
+---+-+---+.....+---+
|3....|...|.....|2..|
|.....|...+-----+...|
|.....|...|2....|...|
|.....|...|.....|...|
|.....|...|.....|...|
+---+-+---+---+-+---+
|3..|1....|...|4....|
|...|.....|...|.....|
|...|.....|...|.....|
|...+-----+...|.....|
|...|1....|...|.....|
+---+.....+---+-+---+
|...|.....|1....|...|
|...|.....|.....|...|
|...|.....|.....|...|
+---+-----+-----+---+
