[manasecret]

Yeah, I was worried about the sloping problem at first. But you can just take the average of the height of the mound, somewhere in the middle between the apex and the sides. It wouldn't be exactly right, but I figured I didn't have to be exactly right because chances were no one would get really close -- I'd either be pretty close or way off. And I was right, if I had more time maybe I would have guessed three layers and would've won.

I meant to use the can as a height reference. But I got distracted playing a game and ran out of time..