You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
dimethyl 2-methyl-1-[(4-methylphenyl)sulfonylamino]-5-(3-methylpyrazin-2-yl)pyrrole-3,4-dicarboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22N4O6S
assistant