You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule ethyl (1R,3S,3aS,6aS)-1-(furan-2-yl)-3,5-dimethyl-4,6-dioxo-1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3-carboxylate into molecular formula.
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C15H18N2O5
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