You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2,4-difluoro-N-[4-(4,5,6,7,8,9-hexahydrocycloocta[d][1,3]thiazol-2-ylamino)-4-oxobutyl]benzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H23F2N3O2S
assistant