import java.util.*;

public class Main {
	public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
		String S = sc.next();

        int N = S.length();
        int Aend = (N-1)/2;
        int Bstart = (N+3)/2;
	
        if(S.substring(0,(N-1)/2). equals (S.substring((N+3)/2-1,N))){
        System.out.println("Yes");
        }else{
        System.out.println("No");
        }
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz