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'.

Title: The Thumbtack. Sentence 1: He yelled at his students, asking who had put it there. Sentence 2: Joe sat down on the bench. Sentence 3: He immediately jumped into the air. Sentence 4: He'd sat on a thumbtack! Sentence 5: They all pretended not to know.
23415