You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(Z)-18-[4-carbamoyl-1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-1H-imidazol-1-ium-5-yl]octadec-9-enoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H45N3O7
assistant