Elim Puzzle

You are given a square board (4×4, 6×6, or 8×8) with numbers as tokens. The sum of the absolute value of all the tokens is the token value count, which is shown on the left.

Select a row

R

by clicking one of the arrows. The arrows for the other rows change to plus and minus signs. Click one of those signs at the end of another row

R'

. Then

R

is replaced by

R+R'

or

R-R'

, according to the sign you clicked. Columns act in a similar way. Zero is not displayed.

The goal is to reduce the token value count as much as possible. Even for the smallest board (4×4) the puzzle is surprisingly hard to solve.