You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1E,3Z,6Z,10Z,14S)-3,7,11-trimethyl-14-propan-2-ylcyclotetradeca-1,3,6,10-tetraene The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H32
assistant