Problem Statement

There are N cards, numbered 1 to N.
Card i has a positive integer A_i written on it.
You can choose three of these cards and concatenate the integers written on them in any order you like to make a new integer. For example, if you choose cards with 1, 23, and 4 written on them, you can make integers such as 1234 and 4231.
Find the maximum integer you can make.

Input

Input is given from Standard Input in the following format:
N
$A_1 A_2 \dots A_N$

Output

Print the answer.

Constraints

• $3 \le N \le 2 \times 10^5$
• $1 \le A_i < 10^6$
• All values in input are integers.

Sample Input 1

5
1 4 3 5 8

Sample Output 1

854

If you choose cards with 4, 5, and 8 written on them, you can make 458, 485, 548, 584, 845, or 854.
You can make nothing greater than 854, so the answer is 854.

Sample Input 2

8
813 921 481 282 120 900 555 409

Sample Output 2

921900813

见题面 Input 部分

见题面 Output 部分