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 N-[2-(1H-benzimidazol-2-yl)ethyl]-2-ethyl-3-methylimidazo[1,2-a]pyridine-6-carboxamide is given. What is its corresponding molecular formula?
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C20H21N5O
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