You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named N-[(3aR,6aR)-3-benzyl-5,5-dioxo-3a,4,6,6a-tetrahydrothieno[3,4-d][1,3]thiazol-2-ylidene]-3-cyclopentylpropanamide by IUPAC nomenclature, provide its molecular formula.
user
C20H26N2O3S2
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