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 4-[2-(3-chloro-4-methylphenoxy)ethylsulfanyl]-2-(2-methylphenyl)-6H-pyrazolo[1,5-a][1,3,5]triazin-7-one into molecular formula.
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C21H19ClN4O2S
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