TASK DEFINITION: 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.
PROBLEM: Sentence1: Bret went mountain climbing in Alaska. Sentence2: He was near the summit of the mountain when a storm struck. Sentence3: Bret had to build a snow cave to keep warm. Sentence4: Bret survived the storm that lasted two days. Sentence5: Bret was glad that he knew mountain survival techniques.

SOLUTION: Bret

PROBLEM: 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.

SOLUTION: Simy, Grandpa, Mom, Grandma

PROBLEM: Sentence1: I woke up one morning and got dressed. Sentence2: I had a package in the mail at the post office. Sentence3: I walked down the street for 20 minutes. Sentence4: When I got the post office, I went to the counter. Sentence5: I was greeted and given a brown box.

SOLUTION:
I (myself)