Not a wish that safe

Little did Jon know that the wish he had just made had been corrupted. Indeed, the stone always granted the wishes the way it could spend the less energy possible. When Jon wished, it quickly analysed that trying to understand what Jon wanted for each wish would cost a lot of energy. So, from now on, instead of granting what Jon meant to wish, the stone would modify what he wants and then grant the wish. For example, if Jon wished to be at school, and the stone calculated that the easiest way to do so was to turn his house into his school, the stone would first make Jon think he wants his house to be turned into his school, and then grant the wish. That way, the stone would still grant the wishes the way Jon wants them to be granted without spending to much energy.