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 (5R)-2-[(1Z)-7-ethenyl-1-ethylidene-2-methyl-2,3-dihydroinden-5-yl]-5-methylcyclopentene-1-carbaldehyde into molecular formula.
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C21H24O
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