Definition: In this task, you're given five sentences, numbered 1 through 5. Your job is to generate a title for the story that makes complete sense. The title must be short, with less than three words, use simple language, and include the main topic of the story.
Input: Sentence 1: Tom hadn't heard his upstairs neighbor move in a long time. Sentence 2: He hadn't seen him outside either. Sentence 3: After a while he went to knock but nobody answered. Sentence 4: He called the authorities just to make sure. Sentence 5: Tom's neighbor had moved out without telling anyone.

Quiet Neighbors