You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by 3-(4-chlorophenyl)-2-[4-(6,8-dibromo-2-oxochromen-3-yl)-1,3-thiazol-2-yl]prop-2-enenitrile ?
user
C21H9Br2ClN2O2S
assistant