You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl 4-[4-[(5-methyl-1,3,4-oxadiazol-2-yl)carbamoyl]piperidin-1-yl]sulfonylbenzoate is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H22N4O6S
assistant