You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule N-[3-(6,7-dihydro-4H-thieno[3,2-c]pyridin-5-yl)-3-oxopropyl]-3-(3-pyridin-3-yl-1,2,4-oxadiazol-5-yl)propanamide into molecular formula.
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C20H21N5O3S
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