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();
    char c[] = S.toCharArray();
    int N = S.length();
    int a = (N-1)/2;
    if(a!=1){
      for(int i=0; i < a; i++){        
        if(c[i] == c[a-1 -i]&&c[a+1 +i] == c[N-1 -i]){
          if(c[a-1 -i] == c[a+1 +i]&&c[i] == c[N-1 -i]){
            
          } else {
            System.out.println("No");
            return;
          }
        } else {
          System.out.println("No");
          return;
        }
      }
    } else {
      if(c[0]!=c[2]) {
        System.out.println("No");
        return;
      }
    }
    System.out.println("Yes");
  }
}