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
#define tie() ios_base :: sync_with_stdio(0); cin.tie(0) ; cout.tie(0);
#define err(x) cerr << #x << " is : " << x << endl
#define mem(a , v)   memset(a , v , sizeof a)
#define all(v)       v.begin() , v.end()
#define pb           push_back
#define ff           first
#define ss           second

bool palin(string p)
{
      int i = 0 , j = p.size() - 1;
      while(i <= j)
      {
            if(p[i] != p[j])
                  return false;
            i++ , j--;
      }
      return true;
}
int32_t main()
{
      tie();
      string s;
      cin >> s;
      int n = s.size();
      bool cond = palin(s);
      s = '.' + s;
      string x = s.substr(1 , ((n - 1) / 2));
      string p = s.substr((n + 3) / 2);
      cond &= palin(x);
      cond &= palin(p);
      if(cond)
            cout << "Yes" << endl;
      else
            cout << "No" << endl;
      return 0;
}