B. Lovely Palindromes

题目连接：

http://www.codeforces.com/contest/688/problem/B

Description

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 ≤ 10100 000).

Output

Print the n-th even-length palindrome number.

Sample Input

1

Sample Output

11

Hint

题意

给你n，问你第n个偶数长度的回文数是哪个

题解

一眼题……

正着输出一遍，再倒着输出一遍就好了。

代码

#include<bits/stdc++.h>
using namespace std;

int main()
{
    string s;
    cin>>s;
    cout<<s;
    for(int i=s.size()-1;i>=0;i--)
        cout<<s[i];
    cout<<endl;
}