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 <bits/stdc++.h>
using namespace std;
#define ll long long
int main() {
   string str; cin>>str; int l=str.length(),c=0,d=0;
   for(int i=0;i<l/2;i++){
     if(str[i]==str[l-i-1])c++;
   } if(c==l/2)d++; c=0;
   for(int i=0;i<l/4;i++){
     if(str[i]==str[l/2-i-1])c++;
   } if(c==l/4)d++; c=0;
   for(int i=0;i<l/4;i++){
     if(str[i+l/2+1]==str[l-i-1])c++;
   }if(c==l/4) cout<<d; if(d==3)cout<<"Yes"; else cout<<"No"; cout<<endl;
}