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: Sam was taking a hike by the lake. Sentence2: He got too close and slipped. Sentence3: Sam fell into the water. Sentence4: He dragged himself out but was soaked. Sentence5: Sam had to go home to change.
Output:
Sam