You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule 2-[(2R,4R)-1,1,1'-trimethyl-2'-oxospiro[2,3-dihydroquinolin-1-ium-4,3'-pyrrolidine]-2-yl]propanoate .
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C18H24N2O3
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