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 (5R)-2-methyl-N-[[(3R)-5-oxo-1-phenylpyrrolidin-3-yl]methyl]-4,5,6,7-tetrahydro-3H-benzimidazole-5-carboxamide is given. What is its corresponding molecular formula?
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C20H24N4O2
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