micro-and-permutation-3
Source: hackerearth
Difficulty: EASY

Micro has just learned about permutations. So he went to Ravi's room to boast about it. But Ravi is very smart, he instead gave him a problem to solve. He gave him an array A of integers of size N. Now Micro has to find a permutation of the numbers such that the number formed by concatenating the numbers of array from left to right is maximized ( see sample explanation for more clarity).

Input:
First line consists of N the size of array. Second line consists of N space separated denoting the array.

Output:
Print the maximum number that is formed by concatenating the numbers of array. (See sample output).

Constraints:
1 ≤ N ≤ 10^5
1 ≤ A[i] ≤ 10^9

SAMPLE INPUT
3
4 32 9

SAMPLE OUTPUT
9432

Explanation

There are six permutations possible:
4, 32, 9. Number formed = 4329
4, 9, 32. Number formed = 4932
9, 4, 32.  Number formed = 9432
9, 32, 4.  Number formed = 9324
32, 9, 4.  Number formed = 3294
32, 4, 9.  Number formed = 3249
Clearly the maximum number is 9432