You will be given a definition of a task first, then some input of the task.
In this task, you're given four sentences of a story written in natural language in which one part is missing. Your job is to predict the position and missing part of the story and return in the following format: position, missing part. The missing part is a sentence that completes the story, and the position is the number of the missing sentence in the new story.

Sentence1: When they went to college, each moved to a different town. Sentence2: Sarah received an unexpected call from David on Friday. Sentence3: They had dinner and talked about their lives. Sentence4: Sarah was glad they were able to catch up.
Output:
1, David and Sarah were friends during childhood.