You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule (3-ethyl-5-methyl-1,2-oxazol-4-yl)-[3-hydroxy-3-(2-methylphenyl)pyrrolidin-1-yl]methanone into molecular formula.
user
C18H22N2O3
assistant