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 <stdlib.h>
#include <string.h>
int main()
{
    char str[105];
    scanf("%s",str);
    int len=strlen(str);
    int i=0,j=len-1;
    int mid=len/2;
    int flag=0;
    int flagi=0;
    for(i=0,j=len-1; i<mid,j>mid; i++,j--)
    {
        if(str[i]!=str[j]) flag=1;
    }
    int ii,jj;
    if(flag==0)
    {

        for(ii=0,jj=mid+1; ii<mid,jj<len; ii++,jj++)
        {
            if(str[ii]!=str[jj]) flagi=1;
        }
        if(flagi==0)
            printf("Yes");
        else
        {
            printf("No");
        }
    }
    else
    {
         printf("No");
    }

    return 0;
}