in build Polycarp live equal number flat floor unfortunately Polycarp do not remember flat floor remember flat number 1 low upper floor that flat floor flat second Polycarp do not remember total number flat building consider build infinitely high ie infinitely floor note floor number 1polycarp remember floor flat locate it guarantee information selfcontradictory it mean exist build equal number flat floor flat Polycarps memory floor Polycarp remembersgiven information possible restore exact floor flat n