You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
12-thiapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1,4,6,8,10,13,15,17,19-nonaene is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H14S
assistant