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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>


int main(){
	char S[100];
	scanf("%s",S);
	int N = strlen(S);
	int NN = N;
	for(int i=0; i<N/2; i++){
		if(S[i] != S[N-1-i]){
			printf("No\n");
			return 0;
		}
	}
	NN = N/2;

		for(int i=0; i<NN/2; i++){
			if(S[i] != S[NN-1-i]){
				printf("No\n");
				return 0;
			}
			else if(S[NN/2+1+i] != S[NN/2+ NN ]){
				printf("No\n");
				return 0;				
			}			
		}
		printf("Yes\n");

	return 0;
}