In python, how do I iterate through elements of a multidimensional array and find its neighbors without using numpy or any imports, just recursion? For example, `minesweeper_board = [[[0, 'b'], [0, 0], [0, 0]], [[0, 0], [0, 0], ['b', 0]], [[0, 0], [0, 0], [0, 0]], [[0, 0], [0, 0], [0, 0]]]` with `'b'` marking a bomb, and I want to update the bomb count around each of the zeros (like in the minesweeper game).