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: Accepted)

#include<bits/stdc++.h>
using namespace std;

int main(){
  string S;
  cin>>S;
  int N=S.length();
  string str1=S.substr(0,(N-1)/2);
  string str2=S.substr(((N+3)/2)-1,N);
  string R=string(S.rbegin(),S.rend());
  string rev1=string(str1.begin(),str1.end());
  string rev2=string(str2.rbegin(),str2.rend());

 if(S==R&&str1==rev1&&str2==rev2&&N>=3&&N<=99){
     cout<<"Yes";
 }
 else{
     cout<<"No";
 }
   return 0;
}