You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[3-(2-amino-2-oxoethyl)-2,4-dioxothietan-3-yl]-5-cyclopropyl-6-[(4-fluorophenyl)methyl]pyridine-2-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C21H18FN3O4S
assistant