You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S)-3-[6-[2-(3-fluorophenyl)ethynyl]pyridazin-3-yl]-1,5,5-trimethylpyrrolidin-2-one is the IUPAC name of a molecule. Please give its molecular formula.
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C19H18FN3O
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