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 Ruby (2.3.3) (judge verdict: Runtime Error)

def parind?(str)
  return true if str.length < 2
  l = str.length/2
  #pp [str, str[0,l], str[str.length-l, l].reverse]
  str[0,l] == str[str.length-l, l].reverse
end

S = gets.chomp
SR = S.reverse
N = S.length
N2 = (N-1)/2
N3 = (N+3)/2

#pp S, SR, N, N2, N3
s1 = S[0,N2]
st = (N+3)/2
s2 = S[st-1, N-st+1]

#pp S, s1, s2

#pp s1, s2

unless parind?(S)
  return puts 'No'
end

unless parind?(s1)
  return puts 'No'
end

unless parind?(s2)
  return puts 'No'
end
puts 'Yes'