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: calculate how many days it will take for 8 boys to paint a 50 m long wall if 6 boys can paint a 60 m long wall in 5 days , 
Options: a ) 4.13 days , b ) 3.13 days , c ) 513 days , d ) 9.13 days , e ) 2 days

Ex Output:
b


Ex Input:
Problem: on my sister ' s birthday , she was 132 cm in height , having grown 10 % since the year before . how tall was she the previous year ? 
Options: a ) 130 cm , b ) 126 cm , c ) 120 cm , d ) 116 cm , e ) 112 cm

Ex Output:
c


Ex Input:
Problem: excluding stoppages , the speed of a train is 45 kmph and including stoppages it is 32 kmph . of how many minutes does the train stop per hour ? 
Options: a ) 17 , b ) 83 , c ) 12 , d ) 83 , e ) 28

Ex Output:

a