You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named methyl 4-[1-(3-chloro-[1,2,4]triazolo[4,3-b]pyridazin-6-yl)piperidin-4-yl]benzoate is given. What is its corresponding molecular formula?
user
C18H18ClN5O2
assistant