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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<string>
using namespace std;
int main(){
  string S;
  cin>>S;
  int N=S.length();
   int sum=0;
/* if(((N-1)/2)%2==0){
    cout<<"No"<<endl;
  }
  else{*/
    string a;
    for(int i=0;i<(N-1)/2;i++){
      a+=S[i];
    }
    string z;
    int j=0;
    for(int i=(N-1)/2-1;i>=0;i--){
      z+=a[i];
    }
    if(a==z){
      string b;
      string y;
      for(int i=(N-1)/2+1;i<N;i++){
      b+=S[i];
    }
      for(int i=(N-1)/2-1;i>=0;i--){
      y+=a[i];
    }
     if(b==y){
       if(a==b){
         cout<<"Yes"<<endl;
       }
       else{
         cout<<"No"<<endl;
       }
     }
    }
    else{
      cout<<"No"<<endl;
    }
 //}
 
 return 0; 
}