Instructions: 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: Adam saw a TV special on lucid dreaming. Sentence2: He tried it that same night. Sentence3: He did the relaxation techniques perfectly. Sentence4: But he just fell asleep and dreamed nothing at all! Sentence5: When he woke the next morning, he was disappointed.
Output:
Adam