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: Wrong Answer)

def isKaibun(s):
    flag = True
    n = 0
    if len(s) > 2:
        if len(s)%2 == 0:
            n = len(s)//2
        else:
            n = (len(s)-1)//2
        for i in range(n):
            if s[i:i+1] != s[len(s)-(i+1):len(s)-i]:
                flag = False
                break
    else:
        flag = False
    return flag
        
s = input()
f = s[:(len(s)-1)//2]
b = s[(len(s)-1)//2+1:]
print(f, b)

if isKaibun(f) and isKaibun(b) and isKaibun(s):
    print('Yes')
else:
    print('No')