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 (3aS,7aR)-5-methyl-2-[[5-(4-methylphenyl)furan-2-yl]methyl]-1,3,4,6,7,7a-hexahydropyrrolo[3,4-c]pyridine-3a-carboxylic acid .
user
C21H26N2O3
assistant