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 INS(x) x.begin(),x.end()
    

    
int main()
{
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    string s;
    cin>>s;

    int l=s.size();
    string rev=s;
    reverse(INS(rev));

    if (rev!=s) {cout<<"No\n"; return 0;}

    string sub=s.substr(0,(l-1)/2);
    string sub2=rev.substr(0,(l-1)/2);
    
    string sub3=sub;
    string sub4=sub2;

    reverse(INS(sub3));
    reverse(INS(sub4));

    if (sub==sub3&&sub2==sub4) cout<<"Yes\n";
    else cout<<"No\n";


    
    return 0;
}