You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named N-[[(3S)-1-(2-phenylethyl)pyrrolidin-3-yl]methyl]-3H-benzimidazole-5-carboxamide is given. What is its corresponding molecular formula?
user
C21H24N4O
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