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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S  = scan.next();
		int N = S.length();
		int f = 0;

		if (N == 3) {
			if (S.charAt(0) == S.charAt(1) && S.charAt(1) == S.charAt(2)) {
			} else {
				f++;
			}

		}

		for (int i = 0; i < N/4; i++) {
			if (S.charAt(i) == S.charAt((N-3)/2-i) && S.charAt((N-3)/2-i) == S.charAt((N+1)/2 + i) && S.charAt((N+1)/2 + i) == S.charAt(N-1-i)) {
			} else {
				f++;
				break;
			}
		}
		if (f == 0) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

	}

}