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: Bianca and her mom were picking carrots from their garden . Bianca picked 26 and her mother picked 15 . If only 16 of the carrots were good , how many bad carrots did they have ?
Example Output: 25

Example Input: 231 birds were sitting in a tree . Some more fly up to the tree . Then there were 312 birds in the tree . How many more fly up to the tree ?
Example Output: 81

Example Input: Sean has 9 apples . Susan gives Sean 8 more . Later , Sean buys 18 tickets at the store . How many apples does Sean have in all ?
Example Output:
17