You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4-fluorophenyl)-3-(2-morpholin-4-ylethylamino)-1,1-dioxo-1-benzothiophene-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22FN3O4S
assistant