You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named (3R)-3-(7,8-dihydro-[1,3]dioxolo[4,5-g]isoquinolin-5-yl)-3-hydroxy-6,7-dimethoxy-2-benzofuran-1-one is given. What is its corresponding molecular formula?
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C20H17NO7
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