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: find the sum the difference between the compound and s . i . on a certain sum of money for 5 years at 20 % per annum is rs . 75 of money ?
Example Output: 1875

Example Input: Problem: 8 years ago , p was half of q ' s age . if the ratio of their present ages is 3 : 4 what will be the total of their present ages ?
Example Output:
28