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 1-[4-[1-(3-chlorophenyl)-5-methylpyrazole-4-carbonyl]piperazin-1-yl]-2-(tetrazol-1-yl)ethanone into molecular formula.
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C18H19ClN8O2
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