You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Input: Consider Input: Context: Zachary did 15 push-ups in gym class today. David did 39 more push-ups than Zachary. John did 9 push-ups less than David. 

 Question: How many more push-ups did Zachary do than John?

Output: 30


Input: Consider Input: Context: There are 11 different books and 17 different movies in the ' crazy silly school ' series. If you read 7 of the books and watched 21 of the movies 

 Question: How many more movies than books have you read?

Output: 14


Input: Consider Input: Context: They decided to hold the party in their backyard. If they have 5 sets of tables and each set has 10 chairs 

 Question: How many more chairs than tables do they have?


Output: 45


