You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[2-[(2-hydroxy-3-methoxyphenyl)methylidene]hydrazinyl]-6-methyl-4H-1,2,4-triazin-5-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C12H13N5O3
assistant