You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[[1-[2-(dimethylamino)ethyl]-2-oxo-5,6,7,8-tetrahydroquinazolin-4-yl]sulfanyl]-N-(5-methyl-1,2-oxazol-3-yl)acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H25N5O3S
assistant