Given the task definition and input, reply with output. 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: Offspring Concert. Sentence 1: When the band started to play, a mosh pit formed in the center. Sentence 2: We were on the floor of an Offspring Concert. Sentence 3: I slowly made my way to the pit and ran around in it. Sentence 4: After a few minutes, I got hit in the face and fell down. Sentence 5: I ended up with a concussion and bloody nose.
12