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.*;
public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    String N=sc.next();
    String n[] =N.split("",0);
    int m=N.length();
    int M=m/2;
    for(int i=0;i<M;i++){
      if(!(n[i].equals(n[m-1-i]))){System.out.println("No");System.exit(0);}
      if(!(n[i].equals(n[M+1+i]))){System.out.println("No");System.exit(0);}}
    int X=M/2;
    for(int j=0;j<X;j++){
      if(!(n[j].equals(n[M-1-j]))){System.out.println("No");System.exit(0);}}
    System.out.println("Yes");
  }
}