Given the task definition and input, reply with output. 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.

Sentence1: Roosevelt was a staunch conservative. Sentence2: He hated his name because it was of a Democrat president. Sentence3: Roosevelt changed his name to Reagan. Sentence4: As he got older, Reagan became more liberal. Sentence5: He regretted his name change.
Reagan, Roosevelt, Democrat president