You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[2-(dimethylamino)ethyl]-3,5,7-trimethyl-N-[[(2S)-oxolan-2-yl]methyl]-1H-indole-2-carboxamide into molecular formula.
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C21H31N3O2
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