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 Julia (0.5.0) (judge verdict: Accepted)

s=chomp(readline())

n=length(s)
flag="Yes"
l=div(n,2)
for i in 1:l
    if s[i]!=s[n-i+1]
        flag="No"
    end
end
l=div(div(n-1,2),2)
for i in 1:l
    if s[i]!=s[div(n-1,2)-i+1]
        flag="No"
    end
end

for i in div(n+3,2):n
    ss=n-(i-div(n+3,2))
    if s[i]!=s[ss]
        flag="No"
    end
end


print(flag)