You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2,4-dimethyl-6-[(2-methyl-1-thiophen-2-ylpropyl)amino]-1,2,4-triazine-3,5-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C13H18N4O2S
assistant