You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Translate the chemical IUPAC name 2-[[4-(aminomethyl)-3-oxo-2,5,6,7,8,8a-hexahydro-1H-isoquinolin-1-yl]sulfanylmethyl]benzoic acid into its molecular formula.
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C18H22N2O3S
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