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: Accepted)

#!/usr/bin/env python3

from sys import stdin, stdout

s = str(input())
length = len(s)
s1, s2, s3 = 0, 0, 0

def palindrome(start, end):

    for i, j in zip(range(start, end), range(end-1, 0, -1)):
        if (j == i):
            return 1
        if (s[i] != s[j]):
            print ("No")
            exit()

s1 = palindrome(0, length)
s2 = palindrome(0, int(((length-1)/2)))
s3 = palindrome(int(((length+3)/2))-1, length)

print ("Yes")