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: Wrong Answer)

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();
	char[] ss = new char[N+2];
	for(int i=1;i<=N;i++) ss[i] = S.charAt(i-1);

	boolean result = true;
	for(int i=1; i<=(N-1)/4; i++){
	    int j=(N-1)/2;
	    if(ss[i]!=ss[j]){
		result = false;
	    }
	    if(ss[i + (N+3)/2]!=ss[j + (N+3)/2]){
		result = false;
	    }
	    j--;
	}
	if(result) System.out.print("Yes");
	else System.out.print("No");
    }
}