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)

import sys
a= str(input())
kaibun = list(a)
n = int(len(kaibun))
answer = "No"
strongn1 = int((n-1)/2)
strongn2 = int((n+3)/2)
for i in reversed(range((int((n+1)/2)),n)):
    if kaibun[i] == kaibun[n-i-1]:
        answer = "Yes"
    else:
        answer = "No"
        print(answer)
        sys.exit()
for i in range(int(strongn1/2)):
    if kaibun[i] == kaibun[strongn1-i-1]:
        answer = "Yes"
    else:
        answer="No"
        print(answer)
        sys.exit()
for i in reversed(range(strongn2,n,int(strongn1/2))):
    if kaibun[i] == kaibun[strongn2-2-i+n]:
        answer = "Yes"
    else:
        answer = "No"
print(answer)