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: Accepted)

program example
	implicit none
    
    character(100) S,A,B
    integer :: N,i,countA=0,countB=0,countS=0
    
    read(*,*) S
    
    S=adjustl(S)
    
    N=len_trim(S)
    
	do i=1,N
    
    	if(S(i:i)==S(N+1-i:N+1-i)) then
        	countS=countS+1
        end if
    
    end do
    
    if(countS/=N) then
    	write(*,*) "No"
        goto 1
    end if
    
    A=S(1:(N-1)/2)
    
    B=S((N+3)/2:N)

	do i=1,(N-1)/2
    
    	if(A(i:i)==A(((N-1)/2)+1-i:((N-1)/2)+1-i)) then
        	countA=countA+1
        end if
    
    end do
    
    do i=(N+3)/2,N
    
    	if(B(i:i)==B(N+((N+3)/2)-i:N+((N+3)/2)-i)) then
        	countB=countB+1
        end if
    
    end do
    
    if(countA==((N-1)/2) .and. countB==((N-1)/2)) then
    	write(*,*) "Yes"
    else
    	write(*,*) "No"
        
    end if
    
1 end program