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 PHP7 (7.0.15) (judge verdict: Runtime Error)

<?php

$s = trim(fgets(STDIN));
$r = strrev($s);
$first = mb_substr($s, 0, ((strlen($s) - 1)/2));
$firstr = strrev($first);
$last = mb_substr($s, ((strlen($s) + 3)/2)-1, strlen($s));
$lastr = strrev($last);

if ($s !== $r) {
    echo "No";
} elseif ($first !== $firstr) {
    echo "No";
} elseif ($last !== $lastr) {
    echo "No";
} else {
    echo "Yes";
}