You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(4-ethoxyphenyl)-5-[(1-ethyl-2,5-dimethylpyrrol-3-yl)methylidene]-2-sulfanylidene-1,3-diazinane-4,6-dione is the IUPAC name of a molecule. Please give its molecular formula.
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C21H23N3O3S
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