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What is the molecular formula of the molecule identified by (3S,3aR,5aR,5bR,7aS,11aS,11bR,13aR,13bS)-3-butan-2-yl-5a,5b,8,8,11a,13b-hexamethyl-1,2,3,3a,4,5,6,7,7a,9,10,11,11b,12,13,13a-hexadecahydrocyclopenta[a]chrysene ?
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C31H54
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