You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3S,4S)-1-[1-(furan-2-ylmethyl)piperidin-4-yl]-4-propylpyrrolidine-3-carboxylic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H28N2O3
assistant