Given a string S, consisting of lowercase Latin characters [a-z]. Find out all the possible palindromes that can be generated using the letters of the string and print them in lexicographical order.
Example 1:
Input: S = abbab
Output:{ abbba babab }
Explanation: abbba and babab are two
possible string whoch are palindrome.
Example 2:
Input: S = abc
Output: {}
Explanation: No permutation is palindromic.

Your Task:
You don't need to read or print anything. Your task is to complete the function all_palindromes() which takes string S as the input parameter and returns a list of strings which are palindrome in lexicographical order.

Expected Time Complexity: O(2^n)
Expected Space Complexity: O(2^n)

Constraints:
1 <= Length of string <= 20

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