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)

/*package whatever //do not write package name here */

import java.io.*;
import java.util.*;
public class Main {
	public static void main (String[] args) {
		Scanner input = new Scanner(System.in);
		String s = input.next();
		int n = s.length();
		String s1 = s.substring(0,(n-1)/2);
		String s2 = s.substring((n+1)/2,n);
		if(isPalin(s)&&isPalin(s1)&&isPalin(s2))
		    System.out.println("Yes");
		else
		    System.out.println("No");
		
	}
	static boolean isPalin(String s)
	{
	    if(s.length()==1)
	        return true;
	    int i=0,j=s.length()-1;
	    boolean flag = false;
	    while(i<j)
	    {
	        if(s.charAt(i)==s.charAt(j))
	            flag = true;
	        else{
	            flag = false;
	            break;
	        }
	        i++;
	        j--;
	    }
	    return flag;
	}
}