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-[2-oxo-1-(2-oxobutyl)-3,4-dihydroquinolin-3-yl]-6H-thieno[2,3-b]pyrrole-5-carboxamide into molecular formula.
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C20H19N3O3S
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