You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 4-(2,4-difluoro-N-methylsulfonylanilino)-N-[2-(4-methoxyphenoxy)ethyl]butanamide is given. What is its corresponding molecular formula?
user
C20H24F2N2O5S
assistant