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: the product of a and b is equal to 12 more than twice the sum of a and b . if b = 10 , what is the value of b - a ? 
Options: a ) 2 , b ) 5 , c ) 7 , d ) 6 , e ) 35

Ex Output:
d


Ex Input:
Problem: dacid obtained 96 , 95 , 82 , 87 and 92 marks ( out of 100 ) in english , mathematics , physics , chemistry and biology . what are his average marks ? 
Options: a ) 67 , b ) 26 , c ) 87 , d ) 26 , e ) 90

Ex Output:
e


Ex Input:
Problem: how many positive even integers less than 100 contain digits 5 or 7 ? 
Options: a ) 10 , b ) 17 , c ) 18 , d ) 19 , e ) 20

Ex Output:

a