You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 1-[2-(1H-benzimidazol-2-yl)pyrrolidin-1-yl]-3-(2-hydroxyphenyl)propan-1-one is given. What is its corresponding molecular formula?
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C20H21N3O2
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