You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2,5-dimethylphenyl)-2-[(3R)-3-(3-methyl-1,2,4-oxadiazol-5-yl)piperidin-1-yl]-2-oxoacetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H22N4O3
assistant