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.

[EX Q]: Sentence1: Alfredo realizes that his stereo system at home is getting old. Sentence2: He decides to look for a replacement. Sentence3: Alfredo buys a great stereo system on sale at a local store. Sentence4: He sets it up at home and it sounds great! Sentence5: Alfredo feels happy now that he has a new stereo system at home.
[EX A]: Alfredo

[EX Q]: Sentence1: Germaine was a scientist working on a secret NASA project. Sentence2: It was meant to help design a ship that could travel to Mars. Sentence3: He was really attracted to a pretty woman who was his colleague. Sentence4: They finally got together and became very intimate. Sentence5: Months later he learned she was a Russian spy and he was fired.
[EX A]: Colleague, Germaine

[EX Q]: Sentence1: Alexis had cut down a Christmas tree in the woods. Sentence2: She brought it home and realized it was too tall. Sentence3: Instead, she set it on it's side. Sentence4: Then, she sawed off the bottom of the tree. Sentence5: When she put it up, it was the right size for her ceiling.
[EX A]:
Alexis