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-[(6,6-dimethyl-2-bicyclo[3.1.1]hept-2-enyl)methyl]-3-ethyl-1-[2-[4-[(E)-3-phenylprop-2-enoyl]piperazin-1-yl]ethyl]urea .
user
C28H40N4O2
assistant