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 <string.h>
int main()
{   
    int a = 0;  /* Sは回文である */
    int b = 0;  /* Sの前半は回文である */
    int c = 0;  /* Sの後半は回文である */
    int index;
    int index2;
    int size;
    char S[1000];
    char temp[1000];
    char temp2[1000];

    scanf("%s", &S);
    size = strlen(S);
    for(index = 0; index < strlen(S); ++index)
        temp[index] = S[size - index - 1];
    temp[index] = '\0';
  //printf("%s %s\n", S, temp);

    if(strcmp(S, temp) == 0)
        a = 1;

    for(index = 0; index < (strlen(S) - 1) / 2; ++index)
        temp[index] = S[index];
    temp[index] = '\0';

    for(index = 0; index < strlen(temp); ++index)
        temp2[index] = temp[strlen(temp) - 1 - index];
  temp2[index] = '\0';
   //printf("%s %s\n", temp, temp2);

    if(strcmp(temp, temp2) == 0)
        b = 1;
    
    for(index = ((strlen(S) + 1) / 2), index2 = 0; index < strlen(S); ++index, ++index2)
        temp[index2] = S[index];
    temp[index2] = '\0';

    for(index = 0; index < strlen(temp); ++index)
        temp2[index] = temp[strlen(temp) - 1 - index];
  temp2[index] = '\0';
  //printf("%s %s\n", temp, temp2);

    if(strcmp(temp, temp2) == 0)
        c = 1;

    if(a == 1 && b == 1 && c == 1)
        printf("Yes\n");
    else   
        printf("No\n");
    return 0;
}