Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

Example Input: michael has some fish in his fish tank . ben gave him 18 more fish . now he has 49 how many fish did he have to begin with ?
Example Output: 31

Example Input: mrs. sheridan has 11 cats . how many more cats does mrs. sheridan need to have 43 cats ?
Example Output: 32

Example Input: danny collects bottle caps . he found 18 bottle caps at the park . now he has 55 bottle caps in his collection . how many bottle caps did danny have at first ?
Example Output:
37