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 9.2.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<string>
using namespace std;
int main()
{
  string s;
  cin>>s;
  int n=s.size();
  int count=0;
  for(int i=0;i<n;i++){
    if(s[i]==s[n-1-i]){
      count++;
    }
  }
  if(count==n){
    int x=(n-1)/2;
    for(int i=0;i<x;i++){
      if(s[i]==s[x-1-i]){
        count++;
      }
    }
    int y=(n+3)/2;
    for(int i=0;i<n;i++){
      if(s[y-1]==s[n-1-i]){
        count++;
        y++;
      }
    }
    if(count==n+x+y){
      cout<<"Yes";
    }
    else{
      cout<<"No";
    }
  }
  else{
    cout<<"No";
  }
  
}