You need to answer a given question containing a blank (_). Your answer must be one of the two objects mentioned in the question, for example "trophy" and "suitcase". Your answer must not contain a word that is not present in the question. Please don't use articles (e.g., the, a) before the answer.

Input: Consider Input: A boy in a house tries to put a big book on a shelf built for paperbacks. The book falls to the ground because the _ is too narrow.

Output: shelf


Input: Consider Input: The professor preferred to teach with the books instead of the computers, because the _ were out of date.

Output: computers


Input: Consider Input: Bob chose to take an online course instead of local school, because the _ uses up- to-date instructional platforms.


Output: online course