You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-(carboxymethyl)-1-(4-hydroxy-3,5-dimethylphenyl)-5-(3-nitrophenyl)-4,6-dioxo-1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3-carboxylic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C23H21N3O9
assistant