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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program main
    implicit none
    integer i, n, m, l, c, flag
    character s*99

    read(*,*) s
    n = len_trim(s)

    flag = 0

    do i = 1, (n-1)/2
        if(s(i:i) == s((n+1-i):(n+1-i))) then
            flag = 0
        else 
            flag = 1
        end if
    end do


    if (flag == 0) then
        m = (n-1)/2

        do i = 1, m/2
            if(s(i:i) == s((m+1-i):(m+1-i))) then
                flag = 0
            else 
                flag = 1
            end if
        end do
    end if
    
    if (flag == 0) then

        l = (n+3)/2
        c = 1

        do i = l, (n-l+1)/2+l
            if(s(i:i) == s((n+1-c):(n+1-c))) then
                flag = 0
            else 
                flag = 1
            end if
            c = c + 1
        end do
    end if


    if (flag == 0) then
        write(*,*) "Yes"
    else
        write(*,*) "No"
    end if

end program