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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String s = sc.next();
        int n = s.length();
        String sub1 = s.substring(0, ((n-1)/2));
        String sub2 = s.substring(((n+3)/2)-1, n );

        if(isPalindrome(s) && isPalindrome(sub1) && isPalindrome(sub2)){
            System.out.println("Yes");
        }else {
            System.out.println("No");
        }

    }

    static boolean isPalindrome(String str)
    {

        // Pointers pointing to the beginning
        // and the end of the string
        int i = 0, j = str.length() - 1;

        // While there are characters toc compare
        while (i < j) {

            // If there is a mismatch
            if (str.charAt(i) != str.charAt(j))
                return false;

            // Increment first pointer and
            // decrement the other
            i++;
            j--;
        }

        // Given string is a palindrome
        return true;
    }
}