You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[3-(4-aminoanilino)sulfanylphenyl]-2-methyl-3-oxo-4H-1,4-benzothiazine-6-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H20N4O2S2
assistant