You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Convert the IUPAC name of a molecule 7-methyl-N-[(3R)-spiro[1-azabicyclo[2.2.2]octane-2,1'-cyclopropane]-3-yl]furo[2,3-c]pyridine-5-carboxamide into molecular formula.
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C18H21N3O2
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