This is a puzzle. You start with six glasses of water, the left three filled and the right three empty. The goal is to have half-full and not full alternating. You are only allowed to move one glass. The arrow keys move the glass up/down/left/right, and "n" and "m" rotate it. Please answer with a number between 1 and 6.
This is based on a puzzle I was told many years ago, probably by my mother.
