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 9.2.1) (judge verdict: Accepted)

#include<stdio.h>
#include<string.h>
int main(void)
{
    char s[100],a,t[100];
    int n,i;
    scanf("%s",s);
    n = strlen(s);
    for(i = 0 ; i < (n - 1)/2 ; i++)
    {
        if(s[i] != s[n - i - 1])
        {
            printf("No");
            return 0 ;
        } 
    }
    for(i = 0; i <= (n-3)/4 ; i++)
    {
        if(s[i] != s[(n-3)/2-i])
        {
            printf("No");
            return 0 ;
        }
    }
    for(i = 0 ; i <= (n-7)/4 ; i++)
    {
        if(s[i + (n+1)/2] != s[n - i-1])
        {
            printf("No");
            return 0 ;
        }
        
    }
    printf("Yes");
    return 0;

}