Two analogies that relate actions to the tools used to perform the action is given in the form "A : B. C : ?". "A : B" relates action A to tool B. Your task is to replace the question mark (?) with the appropriate tool for the given action C, following the "A : B" relation.

Input: Consider Input: drill : drill. vacuum : ?

Output: vacuum


Input: Consider Input: cut : knife. hit : ?

Output: hammer


Input: Consider Input: mop : mop. vacuum : ?


Output: vacuum