Q: 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.
Title: Bob. Sentence 1: My friend Bob was on the bench today. Sentence 2: Bob waved goodbye and went home. Sentence 3: He was unsure if his daughter was coming today. Sentence 4: She showed up a half hour later. Sentence 5: He is getting forgetful.
A:
52