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: Wrong Answer)

using System;
using System.Linq;

class Program
{
	static void Main(string[] args)
	{
		string inputs = "akasaka";//Console.ReadLine();
		int len = inputs.Length;


		if (Calc(inputs.Substring(0, (len - 1) / 2)) == false)
		{
			Console.WriteLine("No");
			return;
		}

		if (Calc(inputs.Substring((len + 2) / 2)) == false)
		{
			Console.WriteLine("No");
			return;
		}

		if (Calc(inputs) == false)
		{
			Console.WriteLine("No");
			return;
		}

		Console.WriteLine("Yes");
	}

	private static bool Calc(string word)
	{
		string revWord = word;
		revWord = new string(revWord.Reverse().ToArray());

		if (word == revWord)
			return true;
		else
			return false;
	}
}