You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by 3-[18-(2-carboxyethyl)-8,13-bis(ethenyl)-3,7,12,17-tetramethyl-1,14,21,22,23,24-hexahydroporphyrin-2-yl]propanoic acid ?
user
C34H38N4O4
assistant