You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 3-(8H-benzo[7]annulen-4-yl)-4-[(Z)-but-1-enyl]-5-ethenyl-N,N-dipropyl-3,4-dihydropyridazin-6-amine by IUPAC nomenclature, provide its molecular formula.
user
C27H35N3
assistant