You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-N-[(1R)-1-(4-fluorophenyl)ethyl]-2-[(4-prop-2-enyl-5-pyridin-4-yl-1,2,4-triazol-3-yl)sulfanyl]propanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22FN5OS
assistant