You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-1-[(3R,5R)-3,5-dimethylpiperazin-1-yl]-4-(2-fluorophenyl)-2-methylbutan-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H25FN2O
assistant