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(non_snake_case)]
#![allow(unused_imports)]
macro_rules!input{(source=$s:expr,$($r:tt)*)=>{let mut iter=$s.split_whitespace();let mut next=||{iter.next().unwrap()};input_inner!{next,$($r)*}};($($r:tt)*)=>{let stdin=std::io::stdin();let mut bytes=std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));let mut next=move||->String{bytes.by_ref().map(|r|r.unwrap()as char).skip_while(|c|c.is_whitespace()).take_while(|c|!c.is_whitespace()).collect()};input_inner!{next,$($r)*}};}macro_rules!input_inner{($next:expr)=>{};($next:expr,)=>{};($next:expr,$var:ident:$t:tt$($r:tt)*)=>{let $var=read_value!($next,$t);input_inner!{$next$($r)*}};}macro_rules!read_value{($next:expr,($($t:tt),*))=>{($(read_value!($next,$t)),*)};($next:expr,[$t:tt;$len:expr])=>{(0..$len).map(|_|read_value!($next,$t)).collect::<Vec<_>>()};($next:expr,chars)=>{read_value!($next,String).chars().collect::<Vec<char>>()};($next:expr,usize1)=>{read_value!($next,usize)-1};($next:expr,$t:ty)=>{$next().parse::<$t>().expect("Parseerror")};}

use std::cmp::{min, max};
use std::collections::{HashMap, HashSet, VecDeque};
use std::mem::swap;


fn main() {
    input!{
        S: String,
    }
    let ans = solve((S,));
    println!("{}", if ans {"Yes"} else {"No"});
}

fn palin(s: &str) -> bool {
    for (c, d) in s.chars().zip(s.chars().rev()) {
        if c!=d {return false;}
    }
    true
}

fn solve((S,): (String,)) -> bool {
    let N = S.len();
    palin(&S[..]) && palin(&S[..(N-1)/2]) && palin(&S[(N+3)/2-1..])
}


#[test]
fn test_solve() {
    //let cases = [("CBABA", 29), ("HEART", 55), ("EARTH", 28), ("IOI", 2)];
    //for (i, (S, a)) in cases.iter().enumerate() {
    //    assert_eq!(solve((S.as_bytes().to_vec(),)), *a, "#{}", i);
    //}
}


/*
    Copyright for the `input!` macro at line #3 is held by Hideyuki Tanaka, 2019.  The
    original macro is licensed under BSD 3-clause license.
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:
 
    1. Redistributions of source code must retain the above copyright notice, this
    list of conditions and the following disclaimer.
 
    2. Redistributions in binary form must reproduce the above copyright notice,
    this list of conditions and the following disclaimer in the documentation
    and/or other materials provided with the distribution.
 
    3. Neither the name of the copyright holder nor the names of its contributors
    may be used to endorse or promote products derived from this software
    without specific prior written permission.
 
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/