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 train 1500 m long can cross an electric pole in 50 sec and then find the speed of the train ? 
Options: a ) 106 , b ) 107 , c ) 108 , d ) 109 , e ) 110

Ex Output:
c


Ex Input:
Problem: a student travels from his house to school at 10 km / hr and reaches school 1 hour late . the next day he travels 12 km / hr and reaches school 1 hour early . what is the distance between his house and the school ? 
Options: a ) 100 , b ) 105 , c ) 110 , d ) 115 , e ) 120

Ex Output:
e


Ex Input:
Problem: x can finish a work in 18 days . y can finish the same work in 15 days . yworked for 5 days and left the job . how many days does x alone need to finish the remaining work ? 
Options: a ) 12 , b ) 5 , c ) 6 , d ) 8 , e ) 9

Ex Output:

a