AT_abc398_f [ABC398F] ABCBA

Find one shortest palindrome that has $ S $ as its prefix.

The input is given from Standard Input in the following format: > $ S $

Print the answer. If multiple solutions exist, any of them is accepted.

### Sample Explanation 1 `ABCBA` is a shortest palindrome that has $ S= $ `ABC` as its prefix. ### Sample Explanation 2 `Z` is a shortest palindrome that has $ S= $ `Z` as its prefix. ### Sample Explanation 3 `TREERT` is a shortest palindrome that has $ S= $ `TREE` as its prefix. ### Constraints - $ S $ is a string of length between $ 1 $ and $ 500000 $ , inclusive, consisting of uppercase English letters.