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 (6aS,11R,12aR,12bR)-11-methyl-1,2,3,5,6,6a,10,11,12a,12b-decahydrochromeno[2,3-g]indolizin-12-one into molecular formula.
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C16H21NO2
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