import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Stream;

/**
 * @author hll[yellowdradra@foxmail.com]
 * @since 2023-03-24 15:40
 **/
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        in.nextLine();
        String s1 = in.nextLine();
        in.nextLine();
        String s3 = in.nextLine();
        String s = Stream.of(s1, s3)
                .flatMap(x -> Stream.of(x.split(" ")))
                .mapToInt(Integer::parseInt)
                .distinct()
                .sorted()
                .mapToObj(String::valueOf)
                .reduce((x, y) -> x + y)
                .orElse("");
        System.out.println(s);
    }
}