In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a man can row upstream at 5 kmph and downstream at 25 kmph , and then find the speed of the man in still water ? 
Options: a ) 15 , b ) 77 , c ) 30 , d ) 88 , e ) 34

Ex Output:
a


Ex Input:
Problem: when working alone , painter w can paint a room in 2 hours , and working alone , painter x can paint the same room in h hours . when the two painters work together and independently , they can paint the room in 3 / 4 of an hour . what is the value of h ? 
Options: a ) 3 / 4 , b ) 1 [ 1 / 5 ] , c ) 1 [ 2 / 5 ] , d ) 1 [ 3 / 4 ] , e ) 2

Ex Output:
b


Ex Input:
Problem: walking at 40 % of his usual speed a man takes 24 minutes more to cover a distance . what is his usual time to cover this distance ? 
Options: a ) 16 , b ) 36 , c ) 42 , d ) 48 , e ) 54

Ex Output:

a