You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 3-O-ethyl 2-O-methyl 6-(trifluoromethylsulfonyloxy)-3,4,4a,5,6,7-hexahydro-1H-isoquinoline-2,3-dicarboxylate into molecular formula.
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C15H20F3NO7S
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