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

Example Input: We ordered 21 pizzas . Each pizza has 8 slices . How many slices of pizza are there altogether ?
Example Output: 168

Example Input: Annie has 6 apples . She gets 6 more from Nathan . Later , Annie buys 10 crayons at the store . How many apples does Annie have in all ?
Example Output: 12

Example Input: The school is planning a field trip . There are 180 students and 60 seats on each school bus . How many buses are needed to take the trip ?
Example Output:
3