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: Accepted)

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

int Check(char *S, int s, int e);

int main(void) {
   
   char S[200];
   
   scanf("%s", S);
   
   int N = strlen(S);
   int ans = Check(S, 0, N - 1);
   
   ans = ans + Check(S, 0, (N - 1)/2 - 1);
   ans = ans + Check(S, (N + 3)/2 - 1, N - 1);
   /*
   printf("%d\n",Check(S, 0, N - 1));
   printf("%d\n",Check(S, 0, (N - 1)/2 - 1));
   printf("%d\n",Check(S, (N + 3)/2 - 1, N - 1));
   */
   if (ans == 0) {
      printf("Yes\n");
   }
   else {
      printf("No\n");
   }
   
   
   return 0;
}

int Check(char *S, int s, int e) {
   
   int i;
   int flag = 0;
   
   for (i = s; i <= e; i++) {
      if (S[i] == S[e - i + s]) {
         flag = 0;
      }
      else {
         flag = 1;
         break;
      }
   }
   
   return flag;
   
}