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 Go (1.6) (judge verdict: Accepted)

package main

import "fmt"

func isPalindrome(S string) bool{
	var ll = len(S)
	for i:=0;i<=ll/2;i++ {
		if S[i] != S[ll - 1  - i] {
			return false
		}
	}
	return true
}

func main(){
	var S string
	fmt.Scanf("%s",&S)
	ll := len(S)
	la := (ll - 1) / 2
	lb := (ll+3) / 2
	S1 := S[0:la]
	S2 := S[lb-1:ll]

	if isPalindrome(S) && isPalindrome(S1) && isPalindrome(S2) {
		fmt.Println("Yes")
		return
	}
	fmt.Println("No ")

}