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;
#define int long long int
#define pb push_back
int fun(string s)
{
    int n=s.size(),i,j;
    for(i=0,j=n-1;i<j;i++,j--)
    {
        if(s[i]!=s[j])
           return 0;
    }
    return 1;
}
signed main()
{
   string s;
   cin>>s;
   int n=s.size();
   string p=s.substr(0,(n-1)/2);
   string q=s.substr((n+3)/2-1,s.size());
  
   if(fun(s)&&fun(p)&&fun(q))
   cout<<"Yes"<<endl;
   else
   cout<<"No"<<endl;
   
}