You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[[(2R,3S,4R)-4-[(4-fluorophenyl)methylamino]-3-hydroxyoxolan-2-yl]methyl]pyridine-4-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H20FN3O3
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