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 3-methoxyspiro[1a,7a-dihydronaphtho[2,3-b]oxirene-7,3'-2,4-dioxatricyclo[7.3.1.05,13]trideca-1(12),5,7,9(13),10-pentaene]-2-one is given. What is its corresponding molecular formula?
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C21H14O5
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