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: Sara had 21 quarters in her bank . Her dad gave her 49 quarters . How many quarters does she have now ?
Example Output: 70

Example Input: In fourth grade there were 10 students at the start of the year . During the year 4 students left and 42 new students came to school . How many students were in fourth grade at the end ?
Example Output: 48

Example Input: Alyssa 's dog had puppies . She gave 7 to her friends . She now has 5 puppies . How many puppies did she have to start with ?
Example Output:
12