Two analogies that relate places/locations to the associated travel mode is given in the form "A : B. C : ?". "A : B" relates place A to travel mode B. Your task is to replace the question mark (?) with the appropriate travel mode for the given place C, following the "A : B" relation.

Example Input: france : airplane. bermuda : ?
Example Output: airplane

Example Input: australia : airplane. downtown : ?
Example Output: subway

Example Input: canada : car. mainland : ?
Example Output:
boat