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>
int main()
{
    char s[100];
    scanf ("%s",&s);//a0 k1 a2 s3 a4 k5 a6
    int l=strlen(s),i,j,d=0,a=1;//l=7
    for (int i=0;i<l/2;i++)
    {
        if (s[i]!=s[l-i-1])
        {
            d=9;
        }
    }
    for (i=(l-1)/2 -1,j=(l+3)/2 -1;i>=((l-1)/2 -1)/2;i--,j++)//i=2,j=4]i=1,j=5]i=0,j=6
    {
        if (s[i]!=s[(l-1)/2 -1-i])//s2#s(2-2)/s2#s0,]s1 s1]s0 =
        {
            d=9;
            break;
        }
        if (s[j]!=s[l-a])//s4#s6]s5#s5]
        {
            d=9;
            break;
        }
        a++;

    }
    if (d==0)
    {
        printf ("Yes");
    }
    else
    {
        printf ("No");
    }
}