You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (3aS,4aR,9aR)-4-hydroxy-4a,5-dimethyl-3-[(4-phenylpiperazin-1-yl)methyl]-3,3a,4,5,6,7,9,9a-octahydrobenzo[f][1]benzofuran-2-one by IUPAC nomenclature, provide its molecular formula.
user
C25H34N2O3
assistant