You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named [3-[1-(cyclopropylmethyl)-5-methylimidazol-2-yl]azetidin-1-yl]-(4-methylpyridin-3-yl)methanone by IUPAC nomenclature, provide its molecular formula.
user
C18H22N4O
assistant