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.

Ex Input:
Fact: Lung cancer is most often caused by exposure to cigarettes. 
Question: What is lung cancer most often caused by exposure to?

Ex Output:
cigarettes.


Ex Input:
Fact: Energy enters ecosystems from the sun. 
Question: The sun contributes what to ecosystems?

Ex Output:
energy.


Ex Input:
Fact: Sea stars use a unique water vascular system with feet. 
Question: Sea stars use a unique water vascular system with what?

Ex Output:

feet.