$(14$ pts$)$ Infix and postfix expressions.

a$)(6$ pts$)$ Convert the following infix expression into postfix.

$a^{{?}^{?}}(b-2^{{?}^{?}}(c+d){)}^{{?}^{{?}^{?}}}2-a**((b-\frac{c}{4-\frac{5}{c+d}})**b)$

Postfix: