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 <iostream>
using namespace std;

bool check_pal(string s){
	int i = 0,j=s.size()-1;
	while(i<=j){
		if(s[i] != s[j]){
			return false;
		}
		i++;
		j--;
	}
	return true;
}

int main() {
	// your code goes here
	string s;
	cin>>s;
	bool full = check_pal(s);
	int indexlow = (s.size()-1)/2;
	string low = s.substr(0, indexlow);
	int indexhi = (s.size()+3)/2;
	int lenhi = s.size() - indexhi + 1;
	cout<<indexhi;
	string high = s.substr(indexhi-1,lenhi);
	bool left = check_pal(low);
	bool right = check_pal(high);
	cout<<s<<" "<<low<<" " <<high<<endl;
	cout<<full<<" "<<left<<" " <<right<<endl;
  	if(!full || !left || !right)
      cout<<"No";
  	else
      cout<<"Yes";
	return 0;
}