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.
Input: Sentence1: Landon was a poor student. Sentence2: His teacher failed him. Sentence3: His parents thought a binder would fix the problem. Sentence4: They bought him a big binder. Sentence5: Landon still failed at school!
Output:
Parents, Teacher, Landon