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

Ex Input:
Problem: the sum of the even numbers between 1 and n is 89 * 90 , where n is an odd number , then n = ?

Ex Output:
179


Ex Input:
Problem: at what rate percent on simple interest will rs . 750 amount to rs . 900 in 8 years ?

Ex Output:
2.5 %


Ex Input:
Problem: in february wilson ’ s earnings were 40 percent of his family ’ s total income . in march wilson earned 25 percent less than in february . if the rest of his family ’ s income was the same in both months , then , in march , wilson ’ s earnings were approximately what percent q of his family ’ s total income ?

Ex Output:

33