You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N'-[2-(4-chlorophenyl)-5,5-dioxo-4,6-dihydrothieno[3,4-c]pyrazol-3-yl]-N-[(2-chlorophenyl)methyl]oxamide by IUPAC nomenclature, provide its molecular formula.
user
C20H16Cl2N4O4S
assistant