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: Karen's Trip. Sentence 1: Karen's job requires long hours at work. Sentence 2: Karen decides that she needs to relax and have some time off. Sentence 3: She works upwards of 80 hours per week. Sentence 4: She books a vacation to Mexico. Sentence 5: Karen travels to Mexico and has a very relaxing vacation.

23