A monk sat with his three students. He took out his fan and placed it in
     front of him, saying, "Without calling it a fan, tell me what this is."
     The first said, "You couldn't call it a slop-bucket."
     The master poked him with his stick. The second picked up the fan and fanned
     himself. He too was rewarded with the stick. The third opened the fan, laid a
     piece of cake on it, and served it to his teacher.
     The teacher said, "Eat your cake."