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)

S=input()
N=len(S)

a=False

for i in range(N):
    if S[i]!=S[N-1-i]:
        print("No")
        break
    else:
        a=True

if a==True:
    for j in range(int((N-3)/2)+1):
        if S[j]!=S[int((N-3)/2)-j]:
            a=False
            print("No")
            break
if a==True:
    for k in range(int((N-3)/2)+1):
        if S[int((N+1)/2)+k]!=S[N-1-k]:
            a=False
            print("No")
            break
if a==True:
    print("Yes")