You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2,3-dihydro-1H-inden-5-ylmethyl)-4-(furan-2-carbonyl)-N'-methylpiperazine-1-carboximidamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H26N4O2
assistant