You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 1-[(1R,5R,6R)-7,7-dimethyl-2-oxabicyclo[3.2.0]heptan-6-yl]-3-[(1S)-1-(5-ethylfuran-2-yl)-2-methoxyethyl]urea .
user
C18H28N2O4
assistant