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 2-[(5-chloro-1-methylbenzimidazol-2-yl)methyl]-1,3,4,5,6,7,8,8a-octahydroisoquinolin-4a-ol into molecular formula.
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C18H24ClN3O
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