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<string.h>
int main()
{
    char ch[100],l,a,b,c;
    int i,j,h,k,n,m,x=0,y=0,z;
    gets(ch);
    n=strlen(ch);
    k=(n-1)/2;
    m=(n+3)/2;
    for(i=0,j=k-1;i<k/2;i++,j--)
    {
        if(ch[i]==ch[j])
        {
            x++;
        }
    }
    for(i=k+1,j=n-1;i<(k+1+(k/2));i++,j--)
    {
        if(ch[i]==ch[j])
        y++;
    }
    if(x==(k/2) && y==(k/2))
        printf("Yes\n");
    else printf("No\n");
    return 0;
}