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 Python (3.4.3) (judge verdict: Runtime Error)

s = str(input())
 
def iskaibun(w)	
	l = int(len(w))
	if w[0:(l-1)/2] == w[(l+3)/2-1:l]:
    	return True
  	else:
      	return False
tf = False
if iskaibun(s) is True:
  	t = len(s)
	if iskaibun(s[0:(t-1)/2]) is True and iskaibun(s[(t+3)/2-1]:) is True:
        tf = True
if tf is True:
    print('Yes')
else:
    print('No')