You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(cyclobutanecarbonyl)-N-[(1R,2S)-1-hydroxy-1-phenylpropan-2-yl]piperidine-4-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H28N2O3
assistant