You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Under IUPAC nomenclature, a molecule named 1'-dibenzofuran-2-ylspiro[1-azapentacyclo[10.7.1.02,7.08,20.014,19]icosa-2,4,6,8(20),9,11,14,16,18-nonaene-13,9'-fluorene] is given. What is its corresponding molecular formula?
user
C43H25NO
assistant