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 (3.8.2) (judge verdict: Accepted)

w = input()
l = len(w)
flag = True
for i in range((l - 1)//2):
  if w[i] != w[l - i - 1]:
    flag = False
    break
mid = (l - 1) // 2
mid_mid = mid // 2
for i in range(mid_mid + 1):
  if w[i] != w[mid - i - 1] or not flag:
    flag = False
    break
  if w[i + mid + 1] != w[l - i - 1]:
    flag = False
    break
if flag:
  print('Yes')
else:
  print('No')