For us slow kids in the back what does this mean, “[…] such that the nine 9-digit numbers formed by the rows of the grid has the highest-possible GCD over any such grid”?
It took 3 readings and a scan of some of the later words but I think this is the correct reading
So a naive program can just solve the puzzle repeatedly, differently, and ccmpute the GCD of the rows, and output the one with the highest result. There aren't infinitely many solutions to a sodoku style puzzle, so...?