Two analogies that signify affordances are given in the form "A : B. C : ?". Affordance is the possibility of an action being done on an object, for example book is an affordance of writing. The phrase "A : B" implies that B is an affordance of A. Your task is to replace the question mark (?) with the appropriate affordance of the given action C, following the "A : B" relation. Your answer should be a single object without further explanation.

Input: Consider Input: write : book. operate : ?

Output: machine


Input: Consider Input: pet : cat. swear : ?

Output: oath


Input: Consider Input: attack : enemy. play : ?


Output: game