while True:
    try:
        len1: int = int(input())
        list1: list = input().split(" ")
        len2: int = int(input())
        list2: list = input().split(" ")
        list3: list = []
        for x in list1 + list2:
            if int(x) not in list3:
                list3.append(int(x))
        list3.sort()
        # print(list3)
        print(int("".join(str(x) for x in list3[::1])))
    except:
        break