You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name ethyl 2-[N-(1,3-dioxoisoindol-2-yl)-N'-(4-fluorophenyl)-N-methylcarbamimidoyl]sulfanylacetate into its molecular formula.
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C20H18FN3O4S
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