9. Combine Lists of Letters

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;


public class _09_CombineListsOfLetters {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char[] firstLine = sc.nextLine().replaceAll("\\W", "").toCharArray();
        char[] secondLine = sc.nextLine().replaceAll("\\W", "").toCharArray();

        List<Character> l1 = new ArrayList<>();
        List<Character> l2 = new ArrayList<>();

        for (int i = 0; i < firstLine.length; i++) {
            l1.add(firstLine[i]);
        }
        for (int i = 0; i < secondLine.length; i++) {
            l2.add(secondLine[i]);
        }

        List<Character> clonel1 = new ArrayList<>(l1);

        for (Character character : l2) {
            if (! clonel1.contains(character)) {
                l1.add(character);
            }
        }


        for (Character character : l1) {
            System.out.print(character + " ");
        }

    }

}