One day, null found a null door that read: 'Solve my riddles!' on the first door there was an equation, they had to add NaN and NaN to unlock the door null screamed out NaN and the door slowly opened with a rumbling noise but on the other side there was another door with another equation, they had to subtract NaN and NaN to unlock the door null screamed out NaN and the door slowly opened with a rumbling noise but on the other side there was another door with another equation, they had to multiply NaN and NaN to unlock the door null screamed out NaN and the door slowly opened with a rumbling noise but on the other side there was another door with another equation, they had to divide NaN and NaN to unlock the door null screamed out NaN and the door slowly opened and on the other side was a nice big chest full of golden coins