<s>[INST] A hotel has 12 floors. On all but one of the floors there is at least one light that is on 24 hours. On the one floor where none of the lights are on 24 hours, there is a sign on every light switch, which says, "Lights are turned off every night at 10.00 P.M.". On all other floors, there is a sign on every light switch that says, "at least one light is always on 24 hours a day. Can the hotel be guaranteed to have one light on 24 hours, if a person goes through all the floors beginning with the first floor, and turns off every light which either has no sign on the switch, or if there is a sign, which is lying?[/INST]