You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(2,6-dichlorophenyl)sulfonylamino]-7-[(5-methyl-1H-imidazol-2-yl)amino]-2-(1,2-oxazolidine-3-carbonylamino)heptanoic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H28Cl2N6O6S
assistant