You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(3aR,6aS)-5-hydroxy-1,2,3,3a,4,5,6,6a-octahydropentalen-2-yl]-4-cyano-N-methylbenzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H20N2O2
assistant