medium-2.txt

_ _ 9   _ 1 _   _ 5 _
_ 7 _   9 _ _   _ 8 _
1 5 _   _ 2 _   _ _ _

6 9 _   _ _ _   2 1 8
_ _ _   1 _ 9   _ _ _
4 1 7   _ _ _   _ 9 3

_ _ _   _ 9 _   _ 4 5
_ 8 _   _ _ 1   _ 7 _
_ 4 _   _ 5 _   9 _ _