You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (8aR,12aR,13aS)-1,2-dimethoxy-8-oxo-N-[(1R)-1-phenylethyl]-5,6,8a,9,10,11,12,12a,13,13a-decahydroisoquinolino[2,1-g][1,6]naphthyridine-3-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C27H33N3O4
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