You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (2R,4aR,8aR)-2-[4-[2-(4-chlorophenyl)ethynyl]phenyl]-6-propyl-1,2,3,4,4a,5,6,7,8,8a-decahydronaphthalene into its molecular formula.
user
C27H31Cl
assistant