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)

def judge(s):
    ok = True
    n = len(s)
    m = (n - 1) // 2
    if (m == 0):
        ok = (s[0] == s[1])
    else:
        for i in range(m):
            if s[i] != s[(n-1)-i]:
                ok = False
                break
    return ok

def strong_judge(s):
    ok = judge(s)
    n = len(s)
    m = (n - 1) // 2
    kf = (m - 1) // 2
    kb = m + kf + 1
    sf = s[0:m]
    sb = s[(m + 1):n]
    if ok:
        ok = judge(sf) and judge(sb)
    return ok

s = str(input())

if ((len(s) % 2 == 0) or (len(s) > 99) or (len(s) < 3)):
    print("No")
else:
    if strong_judge(s):
        print("Yes")
    else:
        print("No")