import java.util.Scanner;
import java.util.TreeSet;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int a = in.nextInt();
            TreeSet<Integer> set = new TreeSet();
            for (int i = 0; i < a; i++) {
                set.add(in.nextInt());
            }
            int b = in.nextInt();
            for (int i = 0; i < b; i++) {
                set.add(in.nextInt());
            }
            for (Integer i : set) {
                System.out.print(i);
            }
        }
    }
}