Aldith, Bogdan and Chedomir are gathered in a medieval tavern. One of them is a knight who always tells the truth, one of them is a knave who always lies, and one of them is a jester who can either tell the truth or lie.
Aldith says, "I am not a knave."
Bogdan says, "I am a knave."
Chedomir says, "I am not a knave."
Who is the jester?