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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

main = do
  s <- getLine
  let n = length s
  let s_1 = take (ceiling ((fromIntegral n - 1) / 2)) s
  let s_2 = drop (ceiling ((fromIntegral n + 3) / 2) - 1) s
  if ck s s_1 s_2 == True
    then putStrLn "Yes"
    else putStrLn "No"

ck :: String -> String -> String -> Bool
ck s1 s2 s3 = and [s1 == reverse s1, s2 == reverse s2, s3 == reverse s3]