You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 2-(7-chloro-4-oxo-3-prop-2-enylquinazolin-2-yl)sulfanyl-N-[(4-fluorophenyl)methyl]-N-methylacetamide into molecular formula.
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C21H19ClFN3O2S
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