You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
15-oxa-17-azatetracyclo[8.7.0.01,14.03,8]heptadeca-2,4,6,8,10,12-hexaene-16-thione The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H11NOS
assistant