A king had three wise men: a Tall one, an Average one, and a Small one. In order to check whether they were really so smart, he came up with a trick.
"Listen, my wise men, I have got five nightcaps: 2 of them are black and 3 are white. I will put a nightcap on each of you and ask you to guess the colour of the nightcap on your head."
The king set the wise men in the order: the Small, the Average, the Tall, so that the Tall could see both of them and the Average could see only the Small one.
"Try guessing!" - the king shouted.
The Tall one replied: "I don't know."
The Average one replied: "I don't know."
The Small thought for a bit and answered:...
So there is a question: What did he say?