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 Kotlin (1.0.0) (judge verdict: Accepted)

fun isKaibun(input: String): Boolean {
    val mid = if(input.length % 2 == 0) { input.length/2 - 1 } else {input.length /2 }
    return (0..mid).map { input[it] == input[input.length - 1 - it] }.all { it }
} 

fun main(args: Array<String>) {
    val S = readLine()!!
    val N = S.length
    if(isKaibun(S) && isKaibun(S.substring(0, ((N - 2)/ 2) + 1)) && isKaibun(S.substring(((N - 1 + 3)/2), N))) { "Yes" } else { "No" }.run(::println)
}