You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N,N-dimethyl-4-(2-methylsulfanylpyridine-3-carbonyl)-2,3-dihydro-1,4-benzoxazine-2-carboxamide by IUPAC nomenclature, provide its molecular formula.
user
C18H19N3O3S
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