You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-chloro-6-fluoro-N-[(4-morpholin-4-ylsulfonylphenyl)methyl]-1-benzothiophene-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H18ClFN2O4S2
assistant