Now A and B are joined by a third person C. You know that one of the three is a knight, one is knave, and one is a spy and each of them knows what the other two are. Knights and knaves behave as usual, but spies may or may not be telling the truth. For each of the following, determine whether there is no solution, a unique solution, or more than one possible solution. List all possible solutions.

a. A says "I am the knight," B says "A is not the knave," and C says "B is not the knave."

b. A says " I am not the spy," B says " I am not the spy," and C says " A is the spy."