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;
string s;
int main(){
	cin >> s;
	int n = s.length();
	//cout << n << " ";
	int ok = 0;
	string tmp = s;
	reverse(s.begin(), s.end());
	if(s != tmp)
		ok = 1;
	string hyy = s.substr(0, (n - 1) / 2);
	string hhh = s.substr((n + 3) / 2 - 1, n);
	//cout << hyy <<" "<< hhh <<endl;
	string t1 = hyy;
	reverse(hyy.begin(), hyy.end());
	string t2 = hhh;
	reverse(hhh.begin(), hhh.end());
	if(hyy != t1)
		ok = 1;
	if(hhh != t2)
		ok = 1;
	if(ok)
		cout << "No" <<endl;
	else
		cout <<"Yes" <<endl;
	return 0;
}