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.split("")

n = s.length

i = n / 2

def f(k)
	l = k.length
	for j in 0..(l/2) do
		if(k[0+j] == k[l-1-j])
		else
			return "No"
		end
	end
	return "Yes"
end

if(n % 2 == 0)
newS_1 = s[0...i]
newS_2 = s[i..n]
else
newS_1 = s[0...i]
newS_2 = s[(i+1)..n]
end

if(f(s) == "Yes" && f(newS_1) == "Yes" && f(newS_2) == "Yes")
	puts "Yes"
else
	puts "No"
end