You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[2-ethyl-5-[(1Z,3Z)-penta-1,3-dienyl]phenyl]-1,3-dimethyl-6H-pyrrolo[3,2-c]carbazole is the IUPAC name of a molecule. Please give its molecular formula.
user
C29H28N2
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