100 prisoners and bulbs of those things (up) _brain

<br/> said 100 inmates were locked up in 100 cells. Outside the cell was an empty room with a light bulb controlled by a switch. At the beginning, the light is off. The guard randomly chooses one of the inmates to enter the room, but guarantees that every prisoner will be chosen infinitely many times. If at some point a prisoner succeeds in determining that everyone has entered the room, all prisoners can be released. Before the game begins, all the inmates can get together to discuss the strategy, but the only thing they can use to communicate is the light bulb. What kind of an agreement should they design? <br/> This classic question is reproduced on the Internet countless, the title description by the good people are changed to the hype, and even added "this lamp forever