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 [(4aR,6aR,8S,10aS,10bR)-2-ethoxycarbonyl-3,4a,7,7,10a-pentamethyl-1,5,6,6a,8,9,10,10b-octahydrobenzo[f]chromen-8-yl]-chloromercury into molecular formula.
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C21H33ClHgO3
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