You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[3-[2-amino-5-(fluoromethyl)-4,4a,5,7-tetrahydrofuro[3,4-d][1,3]thiazin-7a-yl]-4-fluoroanilino]-(5-methoxypyrazin-2-yl)methanol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H21F2N5O3S
assistant