Three Walls

Build the solid that casts all three shadows at once. You are given what a shape looks like from the front, from the side, and from straight above. Nothing else. Stack blocks until all three views match. Matching them is not enough. You are also given a block count, and you have to hit it exactly. The obvious answer - filling in everything the shadows allow - always uses too many. Working out what to leave out is the puzzle. 30 stages, growing from 3x3x3 up to 5x5x5. No timer. Each stage reme