\[\underline{e}\overline{3}\underline{e}\overline{2}\underline{e}\overline{1}\Rightarrow 3\times 2\times 1=6,\overline{3}\underline{e}\overline{2}\underline{e}\overline{1}\underline{e}\Rightarrow 3\times 2=6\Rightarrow 6+6=12\]