You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[6-[(3R)-3-aminopiperidin-1-yl]-4-oxopyrazolo[1,5-a]pyrazin-5-yl]methyl]benzonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H20N6O
assistant