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) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		
		String S = cin.next();
		
		int N = S.length();
		
		int n1 = (N-1)/2-1;
		int n2 = (N+3)/2-1;
		
		boolean flag = true;
		for(int i = 0;i<=n1;i++) {
			if(S.charAt(i)!=S.charAt(n1-i)) {
				flag = false;
				break;
			}
		}
		
		for(int j = n2;j<N;j++) {
			if(S.charAt(j)!=S.charAt(N-1-j)) {
				flag = false;
				break;
			}
		}
		
		if(flag) System.out.println("Yes");
		else System.out.println("No");

	}

}