Broken palindromes P54747

(The original statement in Catalan has some jokes. This English version goes straight to the point of the problem.)

A palindrome has been broken into pieces. Put the pieces together in the right order.

Input

Input consists of several cases. Every case begins with the number of pieces $n$. Follow the $n$ pieces, made up of only lowercase letters. Assume $1 \le n \le 8$.

Output

For every case, print the palindrome that can be made by joining all the pieces. There is always exactly one solution.