Problem:
Score : 200 points

Problem Statement

A string S of an odd length is said to be a strong palindrome if and only if all of the following conditions are satisfied:

S is a palindrome.

Let N be the length of S. The string formed by the 1-st through ((N-1)/2)-th characters of S is a palindrome.

The string consisting of the (N+3)/2-st through N-th characters of S is a palindrome.

Determine whether S is a strong palindrome.

Constraints

S consists of lowercase English letters.

The length of S is an odd number between 3 and 99 (inclusive).

Input

Input is given from Standard Input in the following format:

S

Output

If S is a strong palindrome, print Yes;
otherwise, print No.

Sample Input 1

akasaka

Sample Output 1

Yes

S is akasaka.

The string formed by the 1-st through the 3-rd characters is aka.

The string formed by the 5-th through the 7-th characters is aka.
All of these are palindromes, so S is a strong palindrome.

Sample Input 2

level

Sample Output 2

No

Sample Input 3

atcoder

Sample Output 3

No

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
class Solution
{
    static void Main(String[] args)
    {
 
        var s = Console.ReadLine();
        bool pal=s==new string(s.Reverse().ToArray());
        var left=s.Substring(0,(s.Length-1)/2);
        var right=s.Substring(left.Length+1,left.Length);

        if(pal&&left==new string(left.Reverse().ToArray())&&right==new string(right.Reverse().ToArray())){
            Console.WriteLine("Yes");
        }else{
            Console.WriteLine("No");

        }
    }
 
}