You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2S)-2-amino-1-[4-[(5-ethyl-1,2,4-oxadiazol-3-yl)methyl]piperazin-1-yl]-3-methylbutan-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C14H25N5O2
assistant