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 Rust (1.15.1) (judge verdict: Accepted)

use std::io::{self, BufRead};

fn parin(s: &[u8]) -> bool {
  let n = s.len();
  for i in 0..(n/2) {
    if s[i as usize] != s[(n-1-i) as usize] {
      return false;
    }
  }
  true
}

fn main() {
  let stdin = io::stdin();
  let mut lines = stdin.lock().lines();
  let s = lines.next().unwrap().unwrap();
  let bytes = s.as_bytes();
  let n = bytes.len();
  let ans = if parin(bytes) && parin(&bytes[0..((n-1)/2)]) && parin(&bytes[((n+1)/2)..n]) { "Yes" } else { "No" };
  println!("{}", ans);
}