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Can you give the molecular formula of the molecule tert-butyl (3E,3aR,4aS,7bS)-3-(dimethylaminomethylidene)-2-oxo-3a,4,4a,5,6,7b-hexahydropentaleno[1,2-b]pyrrole-1-carboxylate ?
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C18H26N2O3
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