A Shinro puzzle is an 8x8 square grid. Your job is to locate twelve hidden marbles, based on the clues in the puzzle: numbers and arrows. A number on the top tells you how many marbles are in the column underneath the number. A number on the side tells you how many marbles are in the row next to the number. Each arrow on the puzzle board points to at least one hidden marble. Not every marble has an arrow pointing to it.