Given the task definition and input, reply with output. 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.

Sentence1: My grandma joined a contest in her small hometown. Sentence2: She believed she had the biggest tree, and wanted to win. Sentence3: Her tree was humongous, and very old. Sentence4: She ended up winning the contest, and a check for $100. Sentence5: A picture was posted in the paper of her holding her check.
I (myself), My grandma