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: Allie knew just how to stay cool in the sweltering summer heat. Sentence2: She would fill balloons with water. Sentence3: When it got hot, she would break one over her head. Sentence4: Slowly, Allie filled the balloons. Sentence5: The water from the broken balloon was refreshing.
Allie