You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule 2-methyl-5-[2-oxo-2-[(1R,5R)-6-(pyridin-2-ylmethyl)-3,6-diazabicyclo[3.2.2]nonan-3-yl]ethyl]-1H-pyrimidin-6-one ?
user
C20H25N5O2
assistant