You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-[7-morpholin-4-yl-3-(2,2,2-trifluoroethyl)triazolo[4,5-d]pyrimidin-5-yl]phenyl]-3-thiophen-3-ylurea The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H19F3N8O2S
assistant