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: Consider Input: Sentence1: Jill was lost in the wilderness. Sentence2: She had been hiking by herself and got separated from the trail. Sentence3: Her boyfriend called the police after not hearing from her. Sentence4: A search team was dispatched to the GPS coordinates on her phone. Sentence5: A helicopter found and rescued Jill near a large tree.

Output: Jill, Police, Boyfriend

Input: Consider Input: Sentence1: Tom moved out to the coast. Sentence2: He experienced his first earthquake. Sentence3: It was a minor one. Sentence4: Tom freaked out. Sentence5: His friends made fun of him.

Output: Friends, Tom

Input: Consider Input: Sentence1: The professor gave everyone a final exam. Sentence2: The next day, he expressed his frustration by yelling at the class. Sentence3: He said that 95% of the class failed. Sentence4: We tried to argue about how unfair the test is. Sentence5: After several discussions, he decided to give test retakes.
Output: Professor