(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 ≤ n ≤ 8.

Output

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

Public test cases

**Input**

8 da ba learro zal azo rra ela bad 3 b a a 2 votemos someto 1 pop

**Output**

dabalearrozalazorraelabad aba sometovotemos pop

Information

- Author
- Alex Alvarez
- Language
- English
- Translator
- Original language
- Catalan
- Other languages
- Catalan
- Official solutions
- C++
- User solutions
- C++