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 4-ethyl-3-[2-(5-methylthiophen-2-yl)-1,3-benzoxazol-6-yl]-4,5-dihydro-1H-pyridazin-6-one into its molecular formula.
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C18H17N3O2S
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