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

Ex Input:
Problem: what is the units digit of 17 ^ 83 13 ^ 82 11 ^ 67 ?

Ex Output:
4

Ex Input:
Problem: in traveling from a dormitory to a certain city , a student went 1 / 5 of the way by foot , 2 / 3 of the way by bus , and the remaining 10 kilometers by car . what is the distance , in kilometers , from the dormitory to the city ?

Ex Output:
62

Ex Input:
Problem: if the height of a cone is increased by 140 % then its volume is increased by ?

Ex Output:
140', 'c ) 998', 'd ) 729', 'e ) 2879'