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

Ex Input:
Problem: a certain rectangular crate measures 8 feet by 14 feet by 16 feet . a cylindrical gas tank is to be made for shipment in the crate and will stand upright when the crate is placed on one of its six faces . what should the radius of the tank be if it is to be of the largest possible volume ?

Ex Output:
6


Ex Input:
Problem: a reduction of 20 % in the price of oil enables a house wife to obtain 4 kgs more for rs . 600 , what is the reduced price for kg ?

Ex Output:
30


Ex Input:
Problem: a ' s speed is 20 / 13 times that of b . if a and b run a race , what part of the length of the race should a give b as a head start , so that b beats a by 80 % of the length of the race ?

Ex Output:

87