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.Collections.Generic;
using System.IO;
using System.Linq;

namespace shoboi_program
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            String input = Console.ReadLine();
            var rev = input.Reverse().ToString();
            if (input != rev)
            {
                Console.Write("No");
                return;
            }

            var input2 = input.Substring(0, (input.Length - 1) / 2);
            var rev2 = input2.Reverse().ToString();
            if (input2 != rev2)
            {
                Console.Write("No");
                return;
            }

            var input3 = input.Substring((input.Length + 3) / 2, input.Length);
            var rev3 = input3.Reverse().ToString();
            if (input3 != rev3)
            {
                Console.Write("No");
                return;
            }
        }
    }
}