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:
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 ?

Ex Output:
29


Ex Input:
While on vacation , Megan took 15 pictures at the zoo and 18 at the museum . If she later deleted 31 of the pictures , how many pictures from her vacation did she still have ?

Ex Output:
2


Ex Input:
Jose wandered 4 kilometers at 2 kilometers per hour . How long did Jose wander ?

Ex Output:

2