Problem Description

Today's date is 2015/10/25.

When viewed as a string, all characters (2, 0, 1, 5, /) appear exactly twice in this string.

A string where every character appears exactly twice is called a "Double String".

You are given a string $ S $ consisting only of lowercase alphabets. Output a Double String that includes all characters present in $ S $.

The output string may include characters not present in $ S $, but it must not contain any characters other than lowercase alphabets.

Input Format

The input is given from the standard input in the following format:

$ S $

• The first line contains the string $S\ (1\ ≦\ |S|\ ≦\ 10)$, where $ |S| $ represents the length of the string $ S $.
• $ S $ consists only of lowercase alphabets.
• It is guaranteed that no character appears more than once in the string $ S $.

Output Format

Output a Double String consisting only of lowercase alphabets that includes all characters present in $ S $. There may be multiple valid Double Strings, and you only need to output one of them. End your output with a newline.

Sample Input and Output

Sample Input #1

on

Sample Output #1

noon

Sample Input #2

meat

Sample Output #2

teammate

Notes/Hints

Sample Explanation 1

Strings like onno, onon, oonn, lemonmelon, etc., are also correct answers.

见题面 Input 部分

见题面 Output 部分