I remember back to the days of my youth. My friends and I were participating in Odyssey of the Mind one year, and we had a problem to solve during the state finals.

The goal was to build a bridge that could transport marbles from one side of a 12-inch square to another without anything touching the surface within the square. With a meager set of supplies (postcard, paperclip, rubber band, etc), we scratched our heads for a bit. But in a flash of inspiration, we built a bridge spanning two adjacent sides.

We thought it might've been too clever, so we asked the judges to reiterate the rules. They didn't mention the opposite side. Just another side.

We took home 1st prize.