You will be given a definition of a task first, then some input of the task.
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: Jennifer had physical therapy appointment at her doctor's office. Sentence2: She arrived early so she sat down and waited to be called to the back. Sentence3: She noticed her appointment time passed and no one called her name. Sentence4: Her physical therapist assistant saw her sitting in the waiting area. Sentence5: Jennifer was reminded her appointment was tomorrow.
Output:
Assistant, Doctor, Jennifer