You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1,2,3,4,4a,9a-hexahydro-[1]benzofuro[2,3-c]pyridin-7-yl 4-methoxybenzenesulfonate into molecular formula.
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C18H19NO5S
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