cf688B-Lovely Palindromes

http://codeforces.com/problemset/problem/688/B

B. Lovely Palindromes

time limit per test

1 second

memory limit per test

256 megabytes

Pari has a friend who loves palindrome numbers. A palindrome number is a number that reads the same forward or backward. For example 12321, 100001 and 1 are palindrome numbers, while 112 and 1021 are not.

Pari is trying to love them too, but only very special and gifted people can understand the beauty behind palindrome numbers. Pari loves integers with even length (i.e. the numbers with even number of digits), so she tries to see a lot of big palindrome numbers with even length (like a 2-digit 11 or 6-digit 122221), so maybe she could see something in them.

Now Pari asks you to write a program that gets a huge integer n from the input and tells what is the n-th even-length positive palindrome number?

Input

The only line of the input contains a single integer n (1 ≤ n ≤ 10^100 000).

Output

Print the n-th even-length palindrome number.

Examples

Input

1

Output

11

Input

10

Output

1001

Note

The first 10 even-length palindrome numbers are 11, 22, 33, ... , 88, 99 and 1001.

题意：找第n个偶数位数的对称数字。

思路：逻辑分析题。只看数字的一半（因为是偶数位数），它的一半是n，则它就是第n个符合要求的数。

代码：

 #include <iostream>
 #include <cstring>
 using namespace std;

 #define n 100005

 int main ()
 {
     char s[n];
     cin >> s;
     int len = strlen(s);
     for (int i = ; i < len; i++)
     {
         cout << s[i];
     }
     for (int i = len - ; i >= ; i--)
     {
         cout << s[i];
     }
     cout << endl;
     return ;
 }