contestada

You visit an island of Knights, Knaves, and Spies. Knights always tell the
truth, Knaves always lie, while Spies can say anything (truth or lie). You
meet three inhabitants, John, Bill, and Tom. One is a Knight, one is a Knave,
and one is a Spy. John says: “I am a knight", Bill says: “John is telling the truth,
and Tom says: “I am the spy!". Determine what type of people John, Bill, and
Tom are. (3 marks)