You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (E)-N-[3-[3-chloro-6-[4-chloro-3-(4-methylpiperazin-1-yl)anilino]-2H-pyrazolo[3,4-d]pyrimidin-4-yl]phenyl]-4-(dimethylamino)but-2-enamide ?
user
C28H31Cl2N9O
assistant