You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-(4-chloro-3-morpholin-4-ylsulfonylanilino)-2-oxoethyl]-N-methylthiophene-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H20ClN3O5S2
assistant