want solution for part b. language Scheme and works in Dr.Racket

1.listpicket takes a list and a picket and returns a picketed list. The picketed list is the original list where all the elements are now surrounded by pickets ( there will be only one picket between any two elements). For example:

( listpicket A ( d ( e f g ) h ( g ) ) will return: ( A d A ( ef g ) Ah A ( g) A )

Note that the sub-lists are not affected.

part b: listpicketall after you have done listpicket, expand it so that the pickets are also inserted in the sub-lists. For example:

( listpicketall A ( a ( ( ( b c ) ) e ) ) ) will return ( A a A ( A ( A ( A b A c A) A) A e A) A)