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.

Ex Input:
pull : pliers. wash : ?

Ex Output:
soap


Ex Input:
eat : spoon. scrub : ?

Ex Output:
brush


Ex Input:
eat : spoon. mop : ?

Ex Output:

mop