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

Ex Input:
Problem: how many integers between 1 and 10 ^ 16 are such that the sum of their digits is 2 ? 
Options: a ) 106 , b ) 116 , c ) 126 , d ) 136 , e ) 146

Ex Output:
d


Ex Input:
Problem: if the charge of staying in a student youth hostel $ 18.00 / day for the first week , and $ 14.00 / day for each additional week , how much does it cost to stay for 23 days ? 
Options: a ) $ 160 , b ) $ 350 , c ) $ 282 , d ) $ 274 , e ) $ 286

Ex Output:
b


Ex Input:
Problem: what is the average ( arithmetic mean ) of all the multiples of 10 from 10 to 160 inclusive ? 
Options: a ) 90 , b ) 95 , c ) 70 , d ) 105 , e ) 110

Ex Output:

c