line-mode
space
diff #(list-list)
";"
split
reverse
{
    left-uncons
    nip-b
    save-c
    "-"
    right-cons
    split
        push-c
        itemize
        split
        push-b
        join
    m5
    push-b
        dup
        is-digit
        not
            "-"
            show-space
            member
            @1
            get
        f5
    m5
    join
}
fold
read-nums
sum