You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-N-(4-chlorophenyl)-2-[[5-(4-methoxyphenyl)-1H-1,2,4-triazol-3-yl]sulfanyl]propanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H17ClN4O2S
assistant