You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[(3R)-2,5-dioxo-1-phenylpyrrolidin-3-yl] N'-[(Z)-1-(4-methoxyphenyl)ethylideneamino]carbamimidothioate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H20N4O3S
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