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: Oscar was a very creative and artistic child. Sentence2: His mother wanted to help nurture that creativity. Sentence3: Oscar's mother bought him some sidewalk chalk. Sentence4: Oscar used his sidewalk chalk creatively and made many drawings. Sentence5: Oscar continued making artwork as he grew up.
Oscar, Oscar's mother