I am programming in scheme:

$($define $($sum n$)$

$($if $(>$ n $0)$

$(+$ n $($sum $(-$ n $1)))$

$0)$

$($define $($ReverseEm elems$)$

$($if $($null$?$ elems$)$

$\text{'}()$

$($append $($ReverseEm $($cdr elems$))($list $($car elems$)))))$

$($define $($nonNegative num$)$

$($if $(>=$ num $0)$

num

$0))$

$($define $($JustDolt Ist$)$

$($let $(($non$-$negatives $($map nonNegative Ist$))$

$($positive$-$sum $($sum Ist$)))$

$($if $($null$?$ Ist$)$

$\text{'}()$

$($list $(-($car Ist$)$ positive$-$sum$)))))$

When I do $($JustDoIt $\text{'}(3-14602-5)),$ it says REAL expected. Why, and how do I fix it$?$