Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

Input: Consider Input: Fact: A compass is used to find magnetic north. 
Question: What does a compass find?

Output: magnetic north.


Input: Consider Input: Fact: navigation requires knowing which way to go. 
Question: What requires knowing which way to go?

Output: navigation.


Input: Consider Input: Fact: Electron transport requires oxygen. 
Question: What does electron transport require?


Output: oxygen.