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: Tim has 22 books . Mike has 20 books . How many books do they have together ?
Example Output: 42

Example Input: In 1 week , Mitch 's family drank 0.5 carton of regular milk and 0.1 carton of soy milk . How much milk did they drink in all ?
Example Output: 0.6

Example Input: There are 9 oak trees currently in the park . Park workers had to cut down 2 oak trees that were damaged . How many oak trees will the park have when the workers are finished ?
Example Output:
7