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: A pet store had 36 siamese cats and 18 house cats . During a sale they sold 26 cats . How many cats do they have left ?
Example Output: 28

Example Input: For a birthday party Jerry bought 41 regular sodas and 22 diet sodas . If his fridge would only hold 9 on each shelf , how many shelves would he fill up ?
Example Output: 7

Example Input: Bridget weighs 39 pounds . Martha weighs 2 pounds . How much heavier is Bridget than Martha ?
Example Output:
37