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);
}
}
}
}