$26.$ Consider the context$-$free grammar:

$->$ ; $|$ ;

$->$ id :

$->$int $|$ real $|$ char $|$

array of $|$

record end

; id : int real char array of record end are all terminals.

and the following input program $($view the whole program as one string although it is displayed across multiple lines for better readability. $)$:

id : array of int; id : record id : real; end;

a$)$ Please give the start symbol of the CFG$.$

b$)$ Give a stepby$-$step rightmost derivation for the program.