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 (2.7.1) (judge verdict: Accepted)

s=gets.chomp
nagasa=s.size
han=((nagasa-1)/2).to_i
dame=0
j=nagasa-1
for i in 0..han-1
  if s[i]!=s[j]
    dame=1
  end
  j-=1
end
han1=((han-1)/2).to_i
j=han-1
for i in 0..han1-1
  if s[i]!=s[j]
    dame=1
  end
  j-=1
end
han2=((nagasa+3)/2).to_i
j=nagasa-1
for i in han2-1..nagasa-1
  if s[i]!=s[j]
    dame=1
  end
  j-=1
end
if dame==1
  puts "No"
else
  puts "Yes"
end