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"
#define ll long long
#define lld long double
#define MOD 1000000007
#define inf 1000000000000000000LL
#define pii pair<ll,ll>
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define all(v) v.begin(),v.end()
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
ll power(ll x,ll y, ll md=MOD){ll res = 1;x%=md;while(y){if(y&1)res = (res*x)%md;x *= x; if(x>=md) x %= md; y >>= 1;}return res;}
 
using namespace std;

#define endl '\n'
#define int ll

bool check(string s) {
    int n = s.size();
    for(int i=0;i<n;i++) {
        if(s[i]!=s[n-1-i]) return false;
    }
    return true;
}

signed main() {
    fast;

    string s;
    cin>>s;

    if(s.size()==1) {
        cout<<"Yes";
        return  0;
    }

    int  n = s.size();

    if(check(s) && check(s.substr(0,(n-1)/2))) cout<<"Yes";
    else cout<<"No";
}