Steppu

Alice and Bob are playing a game on a tree. Initially, nodes $A$ and $B$ are painted blue and red respectively, and no other node is painted. The two players take turns, with Alice going first. The game proceeds as follows: - If it is Alice's turn, she will select a node $u$ adjacent to a blue node and paint it blue. - If it is Bob's turn, he will select a node $u$ adjacent to a red