Game of Checkers
On the checkerboard below are placed 40 stones.
20 white and 20 black stones,
all on the white fields. The numbers situated
around the board tell you how many
black (top number) and white (bottom) stones
are situated on the diagonal. In
every column and row are exacly 2 white and
2 black stones. Ten fields stay empty.
How are the stones placed?
