You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[(E)-3-[4-(2-cyclopropylpropan-2-yl)piperazin-1-yl]-3-oxoprop-1-enyl]benzonitrile The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H25N3O
assistant