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: Megan 's class is going on a field trip to the zoo . If each van can hold 5 people and there are 25 students and 5 adults going , how many vans will they need ?
Example Output: 6

Example Input: In fourth grade there were 33 students at the start of the year . During the year 18 students left and 14 new students came to school . How many students were in fourth grade at the end ?
Example Output: 29

Example Input: Carrie 's mom gave her $ 91 to go shopping . She bought a sweater for $ 24 , a T - shirt for $ 6 , and a pair of shoes for $ 11 . How much money does Carrie have left ?
Example Output:
50