That was the initial idea, actually! But after some thought, we realized that it probably wouldn't work well on mobile and would also be hard for people who just want to do a quick puzzle. So we came up with the idea that it's enough for the person to know the algorithm, and we can check it by asking them for the result of two inputs.

Initially, we also had three inputs, but realized it was too boring, while a single input allowed an incorrect algorithm to be right too often!

Would you be interested in having to write the Python function? It could be an optional feature in the game.