You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-(3-hydroxy-3',6',11,12b-tetramethylspiro[1,2,3,4,6,6a,6b,7,8,10,12,12a-dodecahydronaphtho[2,1-a]azulene-9,2'-3,3a,5,6,7,7a-hexahydrofuro[3,2-b]pyridine]-4'-yl)ethyl]-3-phenylpropanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C39H56N2O3
assistant