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What is the molecular formula of the molecule 1-[(4aR,7aS)-1-[(6-methoxy-2,3-dihydro-1H-inden-5-yl)methyl]-6,6-dioxo-2,3,4a,5,7,7a-hexahydrothieno[3,4-b]pyrazin-4-yl]ethanone ?
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C19H26N2O4S
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