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;
int main()
{
    string s;
    cin>>s;
    int flag1=0;
    int flag2=0;
    int n=s.size();
    for(int i=0;i<n;i++)
    {
        if(s[i]!=s[n-1-i])
        {
            flag1=1;
            break;
        }
    }

    if(s[(n-1)/2 -1]!=s[0] || s[(n+3)/2 -1]!=s[n-1])
        flag2=1;

    // cout<< flag1||flag2 ;
    if((flag1 || flag2 )==1)
        cout<<"No";
    else
    {
        cout<<"Yes";
    }
    
    return 0;
}