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: Runtime Error)

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

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

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

        if(n%2==1) return 1;

        fl=0;
        for(i=0;i<n/2;i++){
                if(s[i]==s[n-i-1]) fl++;
        }
        for(i=0;i<(n-1)/2;i++){
                if(s[i]==s[n-i-1]) fl++;
        }
        for(i=0;i<(n+3)/2;i++){
                if(s[i]==s[n-i-1]) fl++;
        }

        if(fl==3) printf("Yes \n");
        else printf("No \n");

        return 0;
}