import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.Set;

public class CombineListsOfLetters {

	public static void main(String[] args) {
		Scanner scn = new Scanner(System.in);
		String firstLine = scn.nextLine();
		String secondLine = scn.nextLine();

		ArrayList<Character> input = new ArrayList<>();
		for (char c : firstLine.toCharArray()) {
			  input.add(c);
			}
		for (char c : secondLine.toCharArray()) {
			  input.add(c);
			}

		Set<Character> s = new LinkedHashSet<Character>(input);
		for (Character character : s) {
			System.out.print(character);
		}