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: Ella wrote her grandma a letter. Sentence2: She went to the post office to mail it. Sentence3: But they told her she needed a stamp! Sentence4: A kind stranger gave little Ella the stamp. Sentence5: Ella happily posted her letter.

Ex Output:
Ella, Stranger, Grandma

Ex Input:
Sentence1: Simy heard her mom speaking to her grandma about a lost letter. Sentence2: She asked her mom what happened. Sentence3: Her mom said her grandma had lost a special letter from her grandpa. Sentence4: Simy felt sad but soon forgot as she played. Sentence5: While putting her toys away she found the letter on a toy shelf.

Ex Output:
Simy, Grandpa, Mom, Grandma

Ex Input:
Sentence1: Sandy and Syd were best friends since kindergarten. Sentence2: While Sandy remained plain looking, Syd blossomed. Sentence3: Syd got the attention of boys, who ignored Sandy. Sentence4: Sandy started spreading rumors about Syd. Sentence5: When Syd cried to her about the gossip, Sandy acted concerned.

Ex Output:
Boys, Friends, Sandy, Syd