Given a statement and question, generate the answer to the question such that the answer is contained in the statement.

Ex Input:
statement: When the arm straightens the elbow straightens., question: What kind of straightens the arm?

Ex Output:
elbow


Ex Input:
statement: weather can change a planet's conditions, question: What can change a planet's conditions?

Ex Output:
weather


Ex Input:
statement: H20 is essential for all animals on earth., question: What is essential for all animals on earth?

Ex Output:

H20