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: Wrong Answer)

#include<stdio.h>
#include<string.h>
#define rep(a,b) for(int i=a;i<=b;i++)

int main(void){
  char s[100]; scanf("%s",&s);
  int len=strlen(s);

  int cnt=0,pnt=0;
  //condition_1
  rep(0,len-1){if(s[i]=s[len-1-i]){cnt+=1;}}
  if(cnt==len){pnt+=1;}
  //condition_2
  cnt=0;
  rep(0,(len-1)/2-1){if(s[i]==s[(len-1)/2-1-i]){cnt+=1;}}
  if(cnt==(len-1)/2){pnt+=1;}
  //conditon_3
  cnt=0;
  rep(0,(len-1)/2-1){if(s[len-1-i]==s[(len-1)/2+1+i]){cnt+=1;}}
  if(cnt==(len-1)/2){pnt+=1;}

  //judge
  if(pnt==3){printf("No\n");}
  else{printf("Yes\n");}

  return 0;
}