Hackerrank Challenges - 3D surface area

(CM) I love this problem. I used it for teaching and visualising 3D arrays -I included "counting the voxels" as part of my implementation, as I explained this to the audience.

There are two parts to the problem: the transformation of a series of 2D arrays into a cube structure, and the actual counting of the faces of every "voxel" in the 3D cube.

This is not a "pythonic solution" - if any such thing exists: code either solves a problem, or it doesn't.