You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (3aS,6aS)-3-(2-methylphenyl)-1-(4-methylphenyl)-5,5-dioxo-3a,4,6,6a-tetrahydrothieno[3,4-d]imidazol-2-one .
user
C19H20N2O3S
assistant