import sys
while True:
    try:
        n1 = int(input())
        L1 = list(map(int, input().split()))
        n2 = int(input())
        L2 = list(map(int, input().split()))
#         L = []
#         #相同的不加入
#         for c in L1:
#             if c not in L:
#                 L.append(c)
#         for c in L2:
#             if c not in L:
#                 L.append(c)
#         L.sort()
        print("".join(map(str,sorted(list(set(L1 + L2))))))

    except:
#         print(sys.exc_info())
        break