题解 | #整型数组合并#

import sys

#for line in sys.stdin:
#    a = line.split()
#    print(int(a[0]) + int(a[1]))

n=int(input())
s1=input().split(" ")

n2=int(input())
s2=input().split(" ")


for x in s2:
    s1.append(x)

s1= list(set(s1))

func=lambda x : int(x)
func2 = lambda x :str(x)
s1=list(map(func,s1))
s1.sort()
s1=list(map(func2,s1))



print("".join(s1))