You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-N-butan-2-yl-6-N-ethyl-4-N-(2-methoxyethyl)-2-methylsulfanylpyrimidine-4,6-diamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C14H26N4OS
assistant