You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[3-(4-amino-7-propan-2-ylpyrrolo[2,1-f][1,2,4]triazine-5-carbonyl)phenyl]-3-(3,4-difluorophenyl)urea is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H20F2N6O2
assistant