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: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;
#define mod (int)1000000007
#define MOD (int)10000000007
#define X 1001100011100001111ll
#define M 26388279066623ll
#define all(a) a.begin(),a.end()
#define for0(i, n) for (int i = 0; i < n; i++)
#define for0e(i, n) for (int i = 0; i <= n; i++)
#define for1(i, n) for (int i = 1; i <= n; i++)
#define loop(i,a,b) for (int i = a; i < b; i++)
#define bloop(i,a,b) for (int i = a ; i>=b;i--)
#define tc(t) int t; cin >> t; while (t--)
#define ll long long
#define pb emplace_back
#define fio ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
#define in(x) scanf("%d", &x)
#define rr return 0
#define prec(n) fixed<<setprecision(n)
#define maxpq priority_queue<int>
#define minpq priority_queue<int, vector<int>, greater<int> >
#define inf (int)(1e18)
#define ini(a, i) memset(a, i, sizeof(a))
#define vi vector<int> 
#define F first
#define S second
#define pi pair<int, int>
#define ppi pair<pair<int,int> , int >
#define vii vector<pi>
const int MAXN = (int)((1e5) + 100);
int max(int a,int b){if(a>b) return a; else return b;}
int min(int a,int b){if(a<b) return a; else return b;} 
int gcd(int a,int b) { if (a == 0) return b; return gcd(b%a, a);}
int cbrt(int x){ int lo=1,hi=min(2000000ll,x);while(hi-lo>1){int mid=(lo+hi)/2;if(mid*mid*mid<x){lo=mid;}else hi=mid;}if(hi*hi*hi<=x) return hi;else return lo;} 
const int dx[4] = {-1, 1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const int N =  (int)(1e6+5); 

bool f(string s,int m,int n){
  int i=m,j=n-1;
  while(i!=j){
    if(s[i] != s[j]){
      return false;
    }
    i++;
    j--;
  }
  return true;
}
signed main(){
  fio;
    string s;
    cin>>s;
    const int n = s.size();
    if(f(s,0,(n-1)/2) && f(s,(n+3)/2,n-1)){
      cout<<"Yes\n";
    }
    else{
      cout<<"No\n";
    }
  rr;
}