You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(3-chloro-4-methyl-N-methylsulfonylanilino)-N-[(Z)-1-(4-iodophenyl)ethylideneamino]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H19ClIN3O3S
assistant