You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S,3aR)-N-(3,4-dichlorophenyl)-3-(4-methoxyphenyl)-3,3a,4,5-tetrahydrobenzo[g]indazole-2-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C25H21Cl2N3O2
assistant