Detailed Instructions: In this task, you're given the title of a story consisting of five sentences, numbered 1 through 5. Your job is to determine which two sentences need to be swapped sentences in order to make a story that makes complete sense and is befittingly titled. Indicate your answer using the numbers of the two sentences in order, such as '34' or '25'. The first digit refers to the sentence which should come first in the story.
Q: Title: Stinky Socks. Sentence 1: He found a pair of rolled-up, stinky socks behind his headboard. Sentence 2: When he returned, he noticed a strange smell in his room. Sentence 3: He washed the sheets and cleaned the floor, but he still smelled it. Sentence 4: For days he searched high and low for that smell. Sentence 5: While Jon was away at summer camp, his cousin Jake stayed in his room.
A:
15