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: Wrong Answer)

def palindrome?(s)
  s.reverse == s
end

s = gets.chomp!
len = s.size

ans = 'Yes'
ans = 'No' unless palindrome?(s)
if (len -1) /2 <= len
  s2 = s.slice(0, (len -1) /2)
  ans = 'No' unless palindrome?(s2)
else
  ans = 'No'
end
if (len+3)/2 +1 < len
  s3 = s.slice((len+3)/2 +1, len)
  ans = 'No' unless palindrome?(s3)
else
  ans = 'No'
end

puts ans