You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(3,4-dimethoxyphenyl)-N-[9-[4-(1H-indole-5-carbonyl)piperazin-1-yl]-9H-fluoren-2-yl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C36H34N4O4
assistant