Direction: The following question consists of fragments of a sentence. The first fragment (1) and the last fragment (6) are in order. The other four fragments are jumbled up and are designated as (P), (Q), (R) and (S). Find out the correct sequence of these from the given alternatives.  

1. If you are serious about 

P. vocabulary building not a hobby, 

Q. you will have to make

R. but an absorbing interest  

S. increasing your vocabulary 

6. Or even an obsession.