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 FastIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    #define rep(i,a,b) for(int i=a; i<b; i++)
    #define ll long long
    #define pb push_back
    #define inf 1e+18L
    #define MOD 1000000007
     
    bool isPalin(string s, int i, int j)
    {
        for(int x=i, y=j; x != y; x++, y--)
        {
            if(s[x] != s[y]) return false;
        }
        return true;
    }
     
    int main()
    {
        FastIO
        string s;
        cin >> s;
        int n = s.size();
        if(isPalin(s,0,n-1))
        {
            if(isPalin(s,0,(n-1)/2 ))
            {
                if(isPalin(s,(n+3)/2 , n-1))
                {
                    cout << "Yes\n";
                }
                else cout << "No\n";
            }
            else cout << "No\n";
        }
        else cout << "No\n";
        return 0;
    }