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.
Input: Title: Jackie. Sentence 1: She assumed that she would never make any new friends. Sentence 2: Jackie was twelve when her family moved away. Sentence 3: Jackie would spend most of her day locked inside her bedroom. Sentence 4: One day her mother enrolled Jackie in an online pen pal club. Sentence 5: She became good friends with another girl her age in the club.
Output:
21