You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethane;4-[(E)-2-[(4Z,5E)-5-ethylidene-3,3-dimethyl-4-propylidenepyrrol-1-ium-2-yl]ethenyl]benzene-1,3-diol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H30NO2+
assistant