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;

string s,s1,s2;
int slen;

bool f(string t)
{
	int tlen=t.size();
	for(int i=0;i<=tlen/2;i++)
	   if(t[i]!=t[tlen-1-i])
	     return false;
	   
	return true;
	
}

int main()
{	
	cin>>s;
	slen=s.size();
	s1=s.substr(0,((slen-1)/2));
	s2=s.substr(((slen+3)/2),slen);
	if(f(s1))
	  if(f(s2))
	    cout<<"Yes";
	  else
	    cout<<"No";
	    
	return 0;
	
}