Missionaries and Cannibals

• The missionaries and cannibals is a problem my Dad showed me.
• You have three missionaries and three cannibals on one side of the river, and they want to cross to the other side.
• They have a boat that can fit two.
• If at any time the cannibals outnumber the missionaries on one side of the river, they eat them.
• How do they get across the river?
• What are the states?
• What are the operators?
• Try it (coins can be used as a model).
• Can you do an exhaustive search?