You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R,3S,4S)-5-[4,5-dimethyl-2-(pentyldiazenyl)anilino]pentane-1,2,3,4-tetrol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H31N3O4
assistant