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: Sam's favorite store was having a huge sale. Sentence2: He thought it was a great opportunity to buy the items he had wanted. Sentence3: When he went to the store, there were people everywhere. Sentence4: He looked for the items he wanted, but everything was gone in his size. Sentence5: He left the store empty handed and disappointed.
Output:
Sam