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: It was my first time skiing and I was not doing well. Sentence2: I skied directly in the path of another skier. Sentence3: The other skier told me his name was Jack and it was nice to meet me. Sentence4: I thought Jack was very polite.
3, We collided and both fell to the ground.