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CSES Problem Set

Palindrome Reorder


Task | Statistics


CSES - Palindrome ReorderCSES - Palindrome Reorder

Time limit:1.00 s Memory limit:512 MB

Given a string, your task is to reorder its letters in such a way that it becomes a palindrome (i.e., it reads the same forwards and backwards).

Input

The only input line has a string of length $n$ consisting of characters A–Z.

Output

Print a palindrome consisting of the characters of the original string. You may print any valid solution. If there are no solutions, print "NO SOLUTION".

Constraints
Example

Input:
AAAACACBA

Output:
AACABACAA