Big Integer

Problem

A Children Marcus (ACM) loves maths, especially large numbers. Marcus loves combine those small integers into a large one.

You, are now another guy who love large numbers, but you are not that idiot, because you are one of the HKU ACM provincists. (not a children Marcus)

While you look at those small integers, what...? that ____ ! <-- think yourself

Input

Each input starts with a positive integer N (≤ 30000). In next lines there are N non-negative integers, each with at most 100 digits. Input is terminated by N = 0, which should not be processed.

Output

For each input set, you have to print the largest possible integer which can be made by appending all the N integers.

Sample Input

4
123 124 56 90
5
123 124 56 90 9
5
9 9 9 9 9
0

Sample Output

9056124123
99056124123
99999

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