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 1-[[2,2-dimethyl-4-(2-oxopyridin-1-yl)-6-(trifluoromethyl)chromen-3-yl]methyl]-3-methylthiourea ?
user
C20H20F3N3O2S
assistant