You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (1S,3aS,3bR,9aR,9bS)-1-hydroxy-11a-methyl-7-oxo-3,3a,3b,4,5,5a,8,9,9a,9b,10,11-dodecahydro-2H-indeno[5,4-f]chromene-1-carbonitrile ?
user
C18H25NO3
assistant