You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(5-chlorothiophen-2-yl)methyl-methylamino]-N-(5-methoxy-2-methyl-4-nitrophenyl)acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H18ClN3O4S
assistant