You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[5-(3-chlorophenyl)-1,3,4-oxadiazol-2-yl]sulfanyl]-N-[4-(cyanomethyl)phenyl]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H13ClN4O2S
assistant