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 2-[(2R)-2-(1-methylpyrrol-2-yl)pyrrolidin-1-ium-1-yl]-N-(2-nitrophenyl)acetamide is given. What is its corresponding molecular formula?
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C17H21N4O3+
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