Rearrange the parts to make a meaningful sentence.

P. may not get seats

Q. on the Diwali train

R. the tickets today, you

S. unless you book

Explanation

1. 01

   "Unless" begins a condition: S "unless you book", then what to book: R "the tickets today," with the main clause's subject, "you".

2. 02

   P gives that subject its verb, "may not get seats", and Q says on which train.

3. 03

   So the order is SRPQ: "Unless you book the tickets today, you may not get seats on the Diwali train."