You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named 3-[[3-(3-benzyl-1,5,6,8-tetrahydroimidazo[1,2-a]pyrazin-4-ium-7-carbonyl)-4-fluorophenyl]methyl]-5-ethyl-1H-pyridazin-6-one;2,2,2-trifluoroacetate by IUPAC nomenclature, provide its molecular formula.
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C29H27F4N5O4
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