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: Allston Christmas. Sentence 1: September 1st, when leases end, is called Allston Christmas in Boston. Sentence 2: He managed to pick up quite a few items. Sentence 3: Scavengers collect usable items often left on sidewalks. Sentence 4: My brother who lives in Allston went scavenging a day early. Sentence 5: Many students live in Allston and throw things away.
A:
25