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.

Ex Input:
Megan has 19 seashells . How many more seashells does she need to find to have 25 seashells in her collection ?

Ex Output:
6


Ex Input:
Mary has 9 yellow marbles . Joan has 3 yellow marbles . How many yellow marbles do they have in all ?

Ex Output:
12


Ex Input:
Before December , customers buy 1346 ear muffs from the mall . During December , they buy 6444 , and there are none . In all , how many ear muffs do the customers buy ?

Ex Output:

7790