KöMaL 2015 K479

In the expression $\big({(-a^{-b})}^{-c}\big)^{-d}$ the numbers 1, 2, 3, 4 are substituted for $a$ , $b$ , $c$ , $d$ in some order. In which case will the value of the expression be a maximum, and in which case will it be a minimum?