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: Roswell Trip. Sentence 1: First he went to the UFO Center. Sentence 2: One day Jackson went to Roswell, New Mexico. Sentence 3: Then he went to the Bottomless Lakes State Park. Sentence 4: Then he stargazed for UFOs, but didn't see anything. Sentence 5: He had a great time.
A:
12