You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[1-(5,6-dihydro-4H-pyrrolo[1,2-b]pyrazol-3-ylmethyl)pyrrolidin-2-yl]-3-(2-hydroxyethyl)quinazolin-4-one into its molecular formula.
user
C21H25N5O2
assistant