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 main(void){
char s[105];
int a,c;
scanf("%s",s);
a=strlen(s)-1;
c=a+1;
for(int b=0;a==b;b++){
if(s[b]!=s[a]){printf("No\n");return 0;}
a--;
}
int d=(c-1)/2-1;
for(int b=0;b==d;b++){
if(s[b]!=s[d]){printf("No\n");return 0;}
d--;
}
int f=strlen(s);
for(int b=(f+3)/2-1;b==f;b++){
if(s[b]!=s[f]){printf("No\n");return 0;}
f--;
}
printf("Yes\n");
}