You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Name the molecular formula for the molecule established as 1-[1-[(2R)-4-aminobutan-2-yl]piperidin-4-yl]-1-(cyclohexylmethyl)-3-ethylurea using the IUPAC nomenclature.
user
C19H38N4O
assistant