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 isP(char ch[])
{
    int l, i, flag=1, tmp, j, tmp2;
    l=strlen(ch);
    for (i=0; i<l/2; i++) {
        if (ch[i]!=ch[l-i-1]) {
            flag=0; break;
        }
    }
    tmp=(l-1)/2;
    for (i=0; i<tmp; i++) {
        if (ch[i]!=ch[tmp-i-1])
            flag=0; break;
    }
    tmp=(l+3)/2;
    tmp2=l-tmp+1;
    j=0;
    for (i=tmp; i<tmp2/2; i++) {
        if (ch[i]!=ch[l-(j)-1])
            flag=0;j++;
            break;
    }
    return flag;
}

int main()
{
    char ch[100];
    int flag;
    scanf("%s", ch);
    flag=isP(ch);
    if (flag) puts("Yes");
    else puts("No");
    return 0;
}