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

Example Input: Problem: what is the sum of natural numbers between 30 and 100
Example Output: 4615

Example Input: Problem: if ( 5 ^ 9 ) ( 9 ^ 5 ) = 3 ( 15 ^ x ) , what is the value of x ?
Example Output: 9

Example Input: Problem: the nasdaq index has decreased by 70 % since year 2000 . how much should the index increase in order to gain the same value as in year 2000 ?
Example Output:
233 %