Definition: In this task, you're given a four sentences of story written in natural language. Your job is to complete end part of the story by predicting appropriate last sentence which is coherent with the given sentences.
Input: Sentence1: Bob had a young puppy. Sentence2: The puppy loved to play catch with Bob. Sentence3: Of course, the puppy grew into a dog. Sentence4: The dog grew old and could no longer play catch.

This made Bob sad.