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(void)
{
    int len;
    int i;
    int score=0;
    int score2=0;
    int scoreb=0;
    int scorec=0;

    char text[100];
    scanf("%s",text);
    len = strlen(text);

    for(i=0;i<=len/2-1;i++){
        if(text[i]==text[len-i-1])
            score++;
    }
    
    if(score == (len-1)/2)
        score2++;
    
    for(i=0;i<=(len-1)/4-1;i++){
        if(text[i]==text[(len-1)/2-i-1])
            scoreb++;
    }

    if(scoreb == (len-1)/4)
        score2++;
    
    for(i=(len+3)/2-1;i<=(3*len+3)/4-1;i++){
        if(text[i]==text[len-1-i])
            scorec++;
    }
    
    if(scorec==(3*len+3)/4 - (len+3)/2 +1)
        score2++;
    
    if(score2 == 3)
        printf("Yes");
    else
        printf("No");

    
    return 0;
}