You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl (1S,2S,4R)-2-ethyl-7-(5-methyl-3-phenyl-1,2-oxazole-4-carbonyl)-7-azabicyclo[2.2.1]heptane-2-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H26N2O4
assistant