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: a train 150 m long is running at a speed of 68 kmph . how long does it take to pass a man who is running at 8 kmph in the same direction as the train ?

Ex Output:
9 sec


Ex Input:
Problem: a man swims downstream 36 km and upstream 18 km taking 3 hours each time , what is the speed of the man in still water ?

Ex Output:

9