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-[2-(furan-2-yl)ethyl]-2-methyl-3-[[4-[(2-oxopyrrolidin-1-yl)methyl]phenyl]methyl]guanidine .
user
C20H26N4O2
assistant