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)

S=input()
N=len(S)
def isPalindrome(s):
  n = len(s)
  flag=True
  slist=list(s)
  for i, c in enumerate(slist):
    if c!=slist[n-1-i]:
      flag=False
    if i > n-i:
      break
  return flag

Slist=list(S)

if isPalindrome(S) and \
   isPalindrome(Slist[0:int((N-1)/2)]) and \
   isPalindrome(Slist[int((N+3)/2)-1:N]):
  print('Yes')
else:
  print('No')