In January 2025, Jane Street posted an interesting puzzle:Fill the empty cells in the grid above with digits such that each row, column, and outlined 3-by-3 box contains the same set of nine unique digits (that is, you’ll be using nine of the ten digits (0-9) in completing this grid), and such that the nine 9-digit numbers (possibly with a leading 0) formed by the rows of the grid has the highest-possible GCD over any such grid.Some of the cells have already been filled in. The answer to this pu...