You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance (3R,3aS,5aR,5bR,7aS,8S,11aS,11bR,13aR,13bS)-5a,5b,8,11a-tetramethyl-3-propan-2-yl-1,2,3,3a,4,5,6,7,7a,8,9,10,11,11b,12,13,13a,13b-octadecahydrocyclopenta[a]chrysene .
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C28H48
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