In this task, you're given the title of a story consisting of five sentences, numbered 1 through 5. Your job is to arrange the sentences in order to make a story that makes complete sense and is apt for the title. Indicate your answer using the number of the sentences in order, such as '34152'.
Example: Title: Marcus Buys Khakis. Sentence 1: All of his clothes were either too formal or too casual. Sentence 2: Marcus needed clothing for a business casual event. Sentence 3: The pair he bought fit him perfectly. Sentence 4: Marcus was happy to have the right clothes for the event. Sentence 5: He decided to buy a pair of khakis.
Example solution: 21534
Example explanation: Marcus's reasons for buying khakis is established, followed by his purchase of them and reaction.

Problem: Title: Leaky Pen. Sentence 1: Tom was at the office signing papers. Sentence 2: The pen he had been using was leaking. Sentence 3: All of a sudden he noticed his hands were blue. Sentence 4: Tom threw the pen away and tried to wash himself. Sentence 5: There was blue ink everywhere.

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Solution: 13524