You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(3R,5R)-3,5-dimethylpiperidin-1-yl]-2-[[5-(2-fluorophenyl)-4-(2-methylpropyl)-1,2,4-triazol-3-yl]sulfanyl]ethanone The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H29FN4OS
assistant