You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl 2-[2-[3-oxo-3-[4-(propylamino)piperidin-1-yl]propyl]imidazol-1-yl]acetate is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H30N4O3
assistant