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

Ex Input:
Problem: the total age of a and b is 12 years more than the total age of b and c . c is how many year younger than a

Ex Output:
12


Ex 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 ?

Ex Output:
900


Ex Input:
Problem: in how many years rs 100 will produce the same interest at 5 % as rs . 200 produce in 2 years at 10 %

Ex Output:

8