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 <stdlib.h>
#include <string.h>

int isRoudingBun(char *s, int length) {
  for (int i = 0; i < (length / 2); i++) {
    if (s[i] != s[length - 1 - i]) return 1;
  }
  return 0;
}

int main() {
  // your code here...
  char kai[100];

  scanf("%s", kai);

  int len = strlen(kai);
  if (isRoudingBun(kai, (len-1)/2) == 0 && isRoudingBun(&kai[(len+3)/2 - 1], len - (len+3)/2 + 1) == 0) {
    printf("Yes\n");
    return 0;
  }

  printf("No\n");
  return 0;
}