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

• ~1 \le n \le 10^6~

Example Input

AAAACACBA

Example Output

AACABACAA