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 (5S)-5-(5-chloro-2-hydroxy-3-methoxyphenyl)-11-ethyl-8-thia-4,6,11-triazatricyclo[7.4.0.02,7]trideca-1(9),2(7)-dien-3-one into molecular formula.
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C18H20ClN3O3S
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