The task is to generate the correct answer for a given math problem.

Example Input: Problem: if a 1 mm thick paper is folded so that the area is halved at every fold , then what would be the thickness of the pile after 50 folds ?
Example Output: 1 billion km', 'e ) none'

Example Input: Problem: the sum of all the digits of the integers from 18 to 21 inclusive is 24 ( 1 + 8 + 1 + 9 + 2 + 0 + 2 + 1 = 24 ) . what is the sum t of all the digits of the integers from 0 to 99 inclusive ?
Example Output: 900

Example Input: Problem: a one - foot stick is marked in 1 / 4 and 1 / 5 portion . how many total markings will there be , including the end points ?
Example Output:
9