Подели според самогласки

import javax.print.DocFlavor;
import java.util.Scanner;

public class PodeliSamoglaski {
    public static boolean isVowel(char c){
        c=Character.toLowerCase(c);
        if(c=='a' || c=='e' || c=='o' || c=='i' || c=='u')
            return true;
        else return false;
    }
    public static void podeli(DLL<Character> list){
        DLL<Character> samoglaski=new DLL<>();
        DLL<Character> soglaski=new DLL<>();

        int n=list.length()/2;
        DLLNode<Character> tmp=list.getFirst();
        DLLNode<Character> tmp2=list.getLast();

        while(n!=0){
            n--;
            if(isVowel(tmp.element)){
                samoglaski.insertLast(tmp.element);
            }else{
                soglaski.insertLast(tmp.element);
            }
            tmp=tmp.succ;

            if(isVowel(tmp2.element)){
                samoglaski.insertLast(tmp2.element);
            }else{
                soglaski.insertLast(tmp2.element);
            }
            tmp2=tmp2.pred;
        }
        if(list.length()%2!=0){
            if(isVowel(tmp.element))
                samoglaski.insertLast(tmp.element);
            else
                soglaski.insertLast(tmp.element);
        }
        System.out.println(samoglaski);
        System.out.println(soglaski);
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        String line=in.nextLine();
        DLL<Character> list=new DLL<>();

        for(int i=0;i<line.length();i++){
            list.insertLast(line.charAt(i));
        }
        podeli(list);
    }
}