You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
What is the molecular formula of the molecule identified by 2-[[(4-ethoxy-3-methoxyphenyl)methyl-methylamino]methyl]-5-(2-fluorophenyl)-4-methyl-1,2,4-triazole-3-thione ?
user
C21H25FN4O2S
assistant