func addListsAdvanced(l1, l2 *list.List) *list.List {
	digitMax := max(l1.Len(), l2.Len()) + 1
	l := list.New()
	pushFrontAtDigit(l1.Front(), l2.Front(), l1.Len(), l2.Len(), l, digitMax)
	return l
}
// addListsAdvanced solves advanced problem 2.5

addListsAdvanced solves advanced problem 2.5
// addListsAdvanced solves advanced problem 2 . 5
func addListsAdvanced(l1, l2 *list.List) *list.List {
	digitMax := max(l1.Len(), l2.Len()) + 1
	l := list.New()
	pushFrontAtDigit(l1.Front(), l2.Front(), l1.Len(), l2.Len(), l, digitMax)
	return l
}
func addListsAdvanced ( l1 , l2 * list . List ) * list . List { digitMax := max ( l1 . Len ( ) , l2 . Len ( ) ) + 1 l := list . New ( ) pushFrontAtDigit ( l1 . Front ( ) , l2 . Front ( ) , l1 . Len ( ) , l2 . Len ( ) , l , digitMax ) return l }
addListsAdvanced solves advanced problem 2.5
addListsAdvanced solves advanced problem 2 . 5