You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 1-[3-[(2-oxopyrrolidin-1-yl)methyl]-1-propan-2-yl-4,6-dihydropyrrolo[3,4-c]pyrazole-5-carbonyl]cyclopentane-1-carbonitrile into molecular formula.
user
C20H27N5O2
assistant