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What is the molecular formula of the molecule identified by (1S,4R)-3-bromo-4,7,7-trimethylbicyclo[2.2.1]hept-2-ene-2-carbaldehyde;(1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one ?
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C21H31BrO2
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