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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>

int main()
{
	char text[100];
	scanf("%s", text);

	int text_len = strlen(text);

	int is_text_palindrome = 0;
	for (int i = 0; i < text_len / 2; i++)
	{
		if (text[i] != text[text_len - i - 1])
			break;
		else if (i == text_len / 2 - 1)
			is_text_palindrome = 1;
	}

	int is_beforetext_palindrome = 0;
	for (int i = 0; i < (text_len - 1) / 4; i++)
	{
		if (text[i] != text[(text_len - 1) / 2 - i - 1])
			break;
		else if (i == (text_len - 1) / 4 - 1)
			is_beforetext_palindrome = 1;
	}

	int is_aftertext_palindrome = 0;
	int count = 0;
	for (int i = (text_len + 3) / 2 - 1; i < text_len - (text_len - 1) / 4 ; i++)
	{
		if (text[i] != text[text_len - count - 1])
			break;
		else if (i == text_len - (text_len -1) / 4 - 1)
			is_aftertext_palindrome = 1;
		else
			count += 1;
	}

	printf("%s", is_text_palindrome && is_beforetext_palindrome && is_aftertext_palindrome
		? "Yes\n" : "No\n");
}