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

Ex Input:
Problem: a , b and c rents a pasture for rs . 730 . a put in 12 horses for 8 months , b 16 horses for 9 months and 18 horses for 6 months . how much should c pay ?

Ex Output:
22


Ex Input:
Problem: the ratio of the radius of two circles is 1 : 3 , and then the ratio of their areas is ?

Ex Output:
1 : 9


Ex Input:
Problem: if the average ( arithmetic mean ) of the 4 numbers 3 , 16 , 33 , and ( n + 1 ) is 20 , then n =

Ex Output:

27