What is the law prohibiting the possibility of creating a perpetual motion machine

What is the law prohibiting the possibility of creating a perpetual motion machine, i.e. a machine that would do more work than energy was expended.

This is the law of friction. Even with the slightest friction, the parts of the perpetual motion machine in contact with each other will create friction, which will (albeit very slowly) extinguish the energy of motion. And this means that more energy will be spent to maintain movement, more will be generated. It is because of friction that the perpetual motion machine will eventually stop and stop working. But placing a perpetual motion machine in a vacuum does not solve the problem. Since there is also gravity, which will sooner or later make him stop.