from functools import cmp_to_key
n = int(input(""))
nums = input("")
a = nums.split(" ")
def cmp(x,y):
    """用于修改排序的操作"""
    if x + y > y + x:
        return -1
    else:
        return 1

a.sort(key=cmp_to_key(cmp))
answer = "".join(a)
if answer[0] == "0":
    print("0")
else:
    print(answer)

还有八个没过，找不到问题在哪，在力扣和牛客网上尝试都过了