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: Accepted)

#include <bits/stdc++.h>
using namespace std;
 
int main() {

string a;
cin >> a;
  int n;
  n=a.size();
  int k;
  k=1;
  for(int i=0;i<n/2;i++)
  {if(a.at(i)!=a.at(n-1-i)){k=0;}}
for(int i=0;i<(n-1)/2/2;i++)
  {if(a.at(i)!=a.at((n-1)/2-1-i)){k=0;}}
  for(int i=(n+3)/2-1;i<n;i++)
  {if(a.at(i)!=a.at(n-1-i+(n+3)/2-1)){k=0;}}
if(k==0){cout<<"No"<<endl;}
      else{cout<<"Yes"<<endl;}
      }