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

//ABC158B
int main(void) {
  int n, k, i, cou=0, tmp;
  char s[99];
  scanf("%s", s);
  for(cou=0; s[cou]!='\0'; ++cou)
    ; //文字数

  for(i=0; i<cou/4; i++){
    if(s[i]!=s[cou/2-1-i]||s[i]!=s[cou/2+1+i]||s[i]!=s[cou-1-i]){
      printf("No");
      return 0;
    }
  }
  printf("Yes");
  return 0;
}