You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-fluoro-N-[(2R)-3-methyl-1-[(6-methylsulfonyl-1,3-benzothiazol-2-yl)amino]-1-oxobutan-2-yl]benzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H20FN3O4S2
assistant