You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 4-[(8aS)-2-(2-carbamoylbenzoyl)-5,5,8a-trimethyl-3,8-dihydro-1H-isoquinolin-6-yl]benzoic acid is given. What is its corresponding molecular formula?
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C27H28N2O4
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