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)

fn read<T: std::str::FromStr>() -> T {
  let mut s = String::new();
  std::io::stdin().read_line(&mut s).ok();
  s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
  read::<String>().split_whitespace()
    .map(|e| e.parse().ok().unwrap()).collect()
}

fn read_vec2<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
  (0..n).map(|_| read_vec()).collect()
}

pub trait LexicalPermutation {
  /// Return `true` if the slice was permuted, `false` if it is already
  /// at the last ordered permutation.
  fn next_permutation(&mut self) -> bool;
}
impl<T> LexicalPermutation for [T] where T: Ord {
  /// Original author in Rust: Thomas Backman <serenity@exscape.org>
  fn next_permutation(&mut self) -> bool {
    // These cases only have 1 permutation each, so we can't do anything.
    if self.len() < 2 { return false; }

    // Step 1: Identify the longest, rightmost weakly decreasing part of the vector
    let mut i = self.len() - 1;
    while i > 0 && self[i-1] >= self[i] {
      i -= 1;
    }

    // If that is the entire vector, this is the last-ordered permutation.
    if i == 0 {
      return false;
    }

    // Step 2: Find the rightmost element larger than the pivot (i-1)
    let mut j = self.len() - 1;
    while j >= i && self[j] <= self[i-1]  {
      j -= 1;
    }

    // Step 3: Swap that element with the pivot
    self.swap(j, i-1);

    // Step 4: Reverse the (previously) weakly decreasing part
    self[i..].reverse();

    true
  }
}
fn main() {
  let s: String = read();
  if check(&s) {
    if check(&s[..s.len()/2].to_string()) && check(&s[(s.len()/2+1)..].to_string()) {
      println!("Yes");
    } else {
      println!("No");
    }
  } else {
    println!("No");
  }

}

fn check(s: &String) -> bool {
  let s: Vec<char> = s.chars().collect();
  let mut ok = true;
  for i in 0..(s.len()/2) {
    if(s[i] != s[(s.len()-1)-i]) { ok = false; }
  }
  ok
}