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 2-[2-(2,3-dihydroindol-1-yl)-2-oxoethyl]-1-ethyl-3-[2-hydroxy-2-(5-methylfuran-2-yl)propyl]guanidine .
user
C21H28N4O3
assistant