You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 3-[(4-methoxyphenyl)methyl]-1,2,4,4a,5,6-hexahydropyrazino[1,2-a]quinoline is given. What is its corresponding molecular formula?
user
C20H24N2O
assistant