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.

Ex Input:
Paul got a box of 479 crayons for his birthday . At the end of the school year , he only had 134 left . How many crayons had been lost or given away ?

Ex Output:
345


Ex Input:
Gary had 73 dollars . He spent 55 dollars on a pet snake . How many dollars did Gary have left ?

Ex Output:
18


Ex Input:
Joyce starts with 75 apples . She gives 52 to Larry . How many apples does Joyce end with ?

Ex Output:

23