You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[(1S)-3-amino-1-[4-chloro-2-fluoro-3-(pyridine-3-carbonyl)phenyl]propyl]propanamide by IUPAC nomenclature, provide its molecular formula.
user
C18H19ClFN3O2
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