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 9.2.1) (judge verdict: Wrong Answer)

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

int main()
{
  char s[100];
  int n,i;

  scanf("%s",s);
  n = strlen(s);

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

  for(i=(n+3)/2; i<(n-(n+3)/2)/2; i++)
  {
    if(s[(n+3)/2 + i] != s[n-i] ){
      printf("No");
      return 0 ;
    }
  }
  printf("Yes");
  return 0;
}