You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[1-[[6-amino-5-(5-methyl-1,3,4-oxadiazol-2-yl)pyrimidin-4-yl]amino]ethyl]-3-cyclopropyl-5-methylquinazolin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H22N8O2
assistant