Introduction to the Theory of Cocktails:
A peasant came to the king and asked, "King, let me take one apple from your garden." The king allowed. The peasant went to the garden and saw: the whole garden is flanked by a triple fence, in each fence there is only one gate, and at each gate there is a guard. When the farmer passed by the first guard, he said to him, "Take the apples, but when you go out, give me half the apples that you will have, and one more." The same said to him the other guards who guarded the gate. How many apples does a farmer have to take in order to bring home one apple after giving the portions to the three guards?