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)

s1=input()
l=len(s1)
h=(l-1)//2
k1=s1[:h]
k2=s1[h+1:]
if k1==k2:
    a=(l-1)//2
    s3=s1[:a]
    if a%2!=0:
        h2=(a-1)//2
        j1=s3[:h2]
        j2=s3[h2+1:]
        if j1==j2:
            b=(l+3)/2
            b2=l-b+1
            s4=s1[:b2]
            h3=(b2-1)//2
            f1=s3[:h3]
            f2=s3[h3+1:]
            if f1==f2:
                print("Yes")
            else:
                print("No")
        else:
            print("No")
    else:
        h2=a/2
        j1=s3[:h2]
        j2=s3[h2+1:]
        if j1==j2:
            b=(l+3)/2
            b2=l-b+1
            s4=s1[:b2]
            h3=(b2-1)//2
            f1=s3[:h3]
            f2=s3[h3+1:]
            if f1==f2:
                print("Yes")
            else:
                print("No")
        else:
            print("No")
else:
    print("No")