If you step the algorithm enough, all maps will eventually become desert and 1 city. If you can prove why, then you prove the collatz conjecture. This computes the collatz function in base 3. Click "step" to progress the algorithm. The sword/hammer can be in 2 modes, DESTROY or BUILD. In BUILD mode, it makes the value higher. 0 becomes 1, 1 becomes 2, and 2 stays as 2, because there is nothing bigger. In DESTROY mode, it does the opposite. 2 becomes 1, 1 becomes 0, and 0 stays 0 because there is no lower value. Whenever the sword/hammer reaches a 1, it switches modes. When the sword/hammer reaches the end, it restarts at the beggining and turns to DESTROY mode. Finally, if the sword/hammer reaches the end in build mode, it builds an extra city tile at the end. Clicking step too quickly might cause errors. Interestingly, even if there is an error, it will still end up as 1 city.