import java.util.Scanner;

class SortLispLists4
{

 public static void main(String[] args) 
 {
  Scanner in = new Scanner(System.in);
  LispList<Integer> ls;
  System.out.print("Enter a list (of integers): ");
  String str = in.nextLine();
  ls = parseIntLispList(str);
  System.out.print("The list you entered is: ");
  System.out.println(ls);
  System.out.print("The list sorted is: ");
  System.out.println(sort(ls));
 }

 public static LispList<Integer> sort(LispList<Integer> ls)
 // Returns a list containing the elements of ls in numerical ascending order.
 // Sorts using insertion sort (expressed using recursion only).
 {
  if(ls.isEmpty())
     return LispList.empty();
  else
     return insert(ls.head(),sort(ls.tail()));
 }

 public static LispList<Integer> insert(Integer n,LispList<Integer> ls1)
 // Assumes ls1 is in ascending numerical order.
 // Returns a list consisting of n inserted into ls1 in the position
 // required to keep ascending numerical order.
 // Implemented using recursion.
 {
  if(ls1.isEmpty())
     return LispList.<Integer>empty().cons(n);
  Integer h = ls1.head();
  if(h.compareTo(n)>0)
     {
      LispList<Integer> ls2 = insert(n,ls1.tail());
      return ls2.cons(h);
     }
  else
     return ls1.cons(n);
 }

 public static LispList<Integer> parseIntLispList(String str)
 {
  String line = str.trim();
  String contents = line.substring(1,line.length()-1).trim();
  if(contents.length()==0)
     return LispList.empty();
  String[] nums = contents.split(",");
  LispList<Integer> list = LispList.empty();
  for(int i=nums.length-1; i>=0; i--)
      {
       String num = nums[i].trim();
       list = list.cons(Integer.parseInt(num));
      }
  return list;
 }

}