You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named methyl (3aR,6aR)-5-(4-nitrophenyl)-4,6-dioxo-3a,6a-dihydro-1H-pyrrolo[3,4-c]pyrazole-3-carboxylate by IUPAC nomenclature, provide its molecular formula.
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C13H10N4O6
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