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-oxo-2-[4-([1,2,4]triazolo[4,3-b]pyridazin-6-yl)piperazin-1-yl]ethyl]benzonitrile into molecular formula.
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C18H17N7O
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