You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[(7-ethenyl-1,4a,7-trimethyl-3,4,6,8,8a,9,10,10a-octahydro-2H-phenanthren-1-yl)methoxy]-3-oxopropanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H34O4
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