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 N-(5-chloropyridin-2-yl)-3-(1,1-dioxothian-4-yl)-2-(6-fluoro-4-oxoquinazolin-3-yl)propanamide is given. What is its corresponding molecular formula?
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C21H20ClFN4O4S
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