You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Can you give the molecular formula of the molecule 3-(6-chloro-5-methylpyridazin-3-yl)-2-(oxan-4-ylmethyl)-3,3a,4,5,6,6a-hexahydro-1H-cyclopenta[c]pyrrol-5-amine ?
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C18H27ClN4O
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