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)

#回文であるか調べる
def kaibuncheck(S):
    N=len(S)
    N_val=N-1
    center=int((N-1)/2)
    checkpoint=0
    for i in range(center-1):
        if S[i] == S[N_val]:
            checkpoint+=1
        N_val -= 1

    if checkpoint == center-1:
        return 1
    else:
        return 0

S = list(input())
N = len(S)
N2 = int((N-1)/2)

S_start=list()
S_end=list()
for i in range(N2):
    S_start.append(S[i])
    S_end.append(S[N-1-i])

if kaibuncheck(S) == 1 and kaibuncheck(S_start) == 1 and kaibuncheck(S_end) == 1:
    print('Yes')
else:
    print('No')