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

Example Input: Kelly had 56 apples . How many more apples does Kelly need to pick to have 105 apples altogether ?
Example Output: 49

Example Input: Gwen was organizing her book case making sure each of the shelves had exactly 4 books on it . If she had 5 shelves of mystery books and 3 shelves of picture books , how many books did she have total ?
Example Output: 32

Example Input: Keith has 20 books . Jason has 21 books . How many books do they have together ?
Example Output:
41