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 b() {
    let mut input = String::new();
    std::io::stdin().read_line(&mut input).expect("input error");
    let s: Vec<char> = input.trim_right().chars().collect();

    let end = (s.len() - 1)/2;
    for i in 0..(end / 2 + 1) {
        if s[i] != s[end - i - 1] {
            println!("No");
            return;
        }
    }

    let begin = (s.len() + 3) / 2;
    for i in (begin - 1)..s.len() {
        if s[i] != s[s.len() - i - 1] {
            println!("No");
            return;
        }
    }
    println!("Yes");
}

fn main() {
    b();
}