Instructions: In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.
Input: Sentence1: Sam was attempting to study at his apartment. Sentence2: His roommate was being way too loud. Sentence3: Sam decided to move to a quieter environment. Sentence4: He drove a few minutes to the coffee shop. Sentence5: Sam was able to study in peace while having a cup of coffee.
Output:
Roommate, Sam