while True:
    try:
        a = input()
        b = map(int,input().split())
        c = input()
        d = map(int,input().split())
        e = []
        #找到不重复的元素,放入空数组
        for i in b:
            if i not in e:
                e.append(i)
        for i in d:
            if i not in e:
                e.append(i)
        #升序排列,无连接符        
        print(''.join(map(str,sorted(e)))) 
        
        
    except:
        break