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: Carlos always loved being near the water. Sentence2: His friend invited him to go sailing one day. Sentence3: Carlos and his friend spent the entire day sailing. Sentence4: It was a great day. Sentence5: Carlos was happy that he had spent the day on the water.

Output: Friend, Carlos

Input: Consider Input: Sentence1: Maddie really wanted a puppy. Sentence2: Her mom told her if she gets all good grades, she could get one. Sentence3: She worked really hard for three months on her school work. Sentence4: When report cards came out, she had earned all a's and b's! Sentence5: Maddie's mom took her to get her puppy as her reward.

Output: Maddie, A puppy, Her mom

Input: Consider Input: Sentence1: It was a hot summer day for Alex. Sentence2: He was tired of feeling hot. Sentence3: So he decided to go take a dip in the lake. Sentence4: He went over and jumped in. Sentence5: Now Alex was cold.
Output: Alex