You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (3aR,6aS)-5-phenyl-2-(pyridin-2-ylmethyl)-3,3a,6,6a-tetrahydro-1H-pyrrolo[3,4-c]pyrrol-4-one into its molecular formula.
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C18H19N3O
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