You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
5-[(4R,10bS)-8-[[(4R)-4-fluoropyrrolidin-3-yl]amino]-4-methyl-3,4,6,10b-tetrahydro-1H-pyrazino[2,1-a]isoindol-2-yl]quinoline-8-carbonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H27FN6
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