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: Wrong Answer)

<?php
$S = fgets(STDIN);
$N = strlen($S);
$S1_kaibun = "";
$S2_kaibun = "";
$l = 0;

for($i = 0; $i < $N; $i++){

$S1_kaibun = $S1_kaibun . substr($S, $N - $i - 1, 1);

}

if(strcmp($S, $S1_kaibun) ==0){
	$l = $l + 1;
}

$S1_kaibun = "";

for($i = 0; $i < ($N - 1) / 2; $i++){

$S1_kaibun = $S1_kaibun . substr($S, $i, 1);

}

for($i = 0; $i < $N; $i++){

$S2_kaibun = $S2_kaibun . substr($S1_kaibun, $N - $i - 1, 1);

}

if(strcmp($S1_kaibun, $S2_kaibun) ==0){
	$l = $l + 1;
}

$S1_kaibun = "";
$S2_kaibun = "";

for($i = ($N + 3) / 2 - 1; $i < $N; $i++){

$S1_kaibun = $S1_kaibun . substr($S, $i, 1);

}
for($i = 0; $i < $N; $i++){

$S2_kaibun = $S2_kaibun . substr($S1_kaibun, $N - $i, 1);

}

if(strcmp($S1_kaibun, $S2_kaibun) ==0){
	$l = $l + 1;
}
if($l == 3){
	echo "Yes";
}else{
	echo "No";
}






?>