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)

#![allow(unused_imports)]

mod pcl {

}




fn is_good(s: &str) -> bool {
    let b = s.as_bytes();
    let l = s.len();
    if l <= 1 {
        true
    } else if b[0] != b[l - 1] {
        false
    } else {
        is_good(&s[1..(l - 1)])
    }
    
    
    
    
    
}

fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let s = s.trim();

    
    
    

    let n = s.len();
    if is_good(&s) && is_good(&s[..((n - 1) / 2)]) && is_good(&s[((n + 1) / 2)..]) {
        println!("Yes");
    } else {
        println!("No");
    }
}