MathDB

Given a

9\times 9

grid, we assign either

+1

-1

to each square on the grid. We define an adjustment as follow: for each square on the grid, we make a product of all numbers of those squares which share a common side with the square (excluding itself).Then we have

81

products. Next we replace all the squares’ values with their corresponding products. Determine if we can make all values in the grid equal to

1

through finite adjustments.

Problem Statement