You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(R)-(5-amino-1,3,4-thiadiazol-2-yl)-phenylmethyl]-3-oxo-4H-1,4-benzoxazine-7-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H15N5O3S
assistant