You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[(2-methyl-2,3-dihydroindol-1-yl)methyl]-N-(6-methylpyridin-2-yl)furan-3-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C21H21N3O2
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