In this task, you are given a sentence and a question, you would be asked to create the answer which is contained in the sentence provided.

Input: Consider Input: Sentence: In weather terms, the boundary between two air masses is called front. Question: In weather terms, what do you call the boundary between two air masses?

Output: front


Input: Consider Input: Sentence: There are four classes of biochemical compounds. Question: How many classes of biochemical compounds are there?

Output: four


Input: Consider Input: Sentence: Depth and density are the two factors that affect the pressure of fluids. Question: What are the two factors that affect the pressure of fluids?


Output: depth and density