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.

Ex Input:
Sentence1: It was early December. Sentence2: My mom had been fighting cancer. Sentence3: She knew her time was near. Sentence4: She promised she would look after me in heaven. Sentence5: She died in her sleep.

Ex Output:
I (myself), My mom

Ex Input:
Sentence1: I walked to my classroom. Sentence2: I was confused since no person waiting outside of the room. Sentence3: My friend eventually came. Sentence4: He told me that class was cancelled for today. Sentence5: I started to head home.

Ex Output:
I (myself), Friend

Ex Input:
Sentence1: Nick went to trim the tree in the backyard. Sentence2: He chopped off all of the branches that he could reach. Sentence3: Hidden in the branches was a large beehive. Sentence4: Without thinking he nudged the beehive. Sentence5: Suddenly hundreds of bees flew out and stung him all over his body!

Ex Output:
Nick, Bees