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.Linq;
public class Hello{
    public static void Main(){
        
        var line = System.Console.ReadLine();
        int n = line.Length;
        string result = "";
        
        var linerev = new string(line.Reverse().ToArray());
        if(line == linerev)
        {
            string cut = line.Substring(0,(n - 1)/2);
            var cutrev = new string(cut.Reverse().ToArray());
            
            if(cut == cutrev)
            {
                result = "Yes";
            }
            else
            {
                result = "No";
            }
        }
        else
        {
            result = "No";
        }
        
        System.Console.WriteLine(result);
    }
}