You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[(1S)-1-amino-2-[(1S,3S,5S)-3-cyano-2-azabicyclo[3.1.0]hexan-2-yl]-2-oxoethyl]-N,N-dimethyl-8-azabicyclo[3.2.1]octane-8-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H27N5O2
assistant