You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[4-[(5-cyclopropyl-1H-pyrazol-3-yl)amino]-6-[(E)-2-(3-fluorophenyl)ethenyl]-1,3,5-triazin-2-yl]piperazin-2-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H21FN8O
assistant