John and Jack walk into a bakery shop. As soon as they enter the bakery, Jack steals three pastries and puts them in his pocket. He says to John: “See how clever I am? The owner didn’t see anything, and I have three free pastries.

John says to Jack: “That’s very dishonest . I am going to show you an honest way to get the same 3 pastries without stealing or lying and prove that I am cleverer than you!”

John says to the owner of the bakery: “Give me a pastry and I will show you a magic trick!”

The owner accepts John’s offer and gives him a pastry. John eats it and asks for another one. The owner gives him another one. John eats that one, asks for a third pastry, and eats that, too.

The owner asks: “What is the magic trick?”

John replies: “Look in Jack’s pocket!”