You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-N,4-N-diethyl-2-methyl-1-N-[2-[4-(tetrazol-1-yl)piperidin-1-yl]pyrimidin-4-yl]benzene-1,4-diamine is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H29N9
assistant