You are given a math word problem and you are supposed to apply multiple mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

Example Input: a pile of clean white paper was stacked in the corner of her room . she decided to place these papers in paper envelopes which can contain 10 white papers . how many paper envelopes does she need if she has 120 clean white papers ?
Example Output: 12

Example Input: the school is planning a field trip . there are 60 students and 10 seats on each school bus . how many buses are needed to take the trip ?
Example Output: 6

Example Input: a company was offering a special on cell phones for $ 2 each . but only if you spent 7 dollars a month for 4 months . how much would it end up costing you total if you bought 1 phone ?
Example Output:
30