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: Nature. Sentence 1: Beth said she must have walked through some poison ivy. Sentence 2: Beth warned her not to walk off the trail, but Barbara didn't listen. Sentence 3: Even if there was thick foliage and leaves, Barbara wandered through. Sentence 4: The next day, Barbara felt itchy all over. Sentence 5: Barbara walked down the forest trail with her older sister Beth.
A:
51