import java.util.*;
class Main{
    public static void main(String[] args){
	Scanner stdIn = new Scanner(System.in);
	String S = stdIn.next();
	int N = S.length();
	String mae = S.substring(0,N/2);
	String ato = S.substring(N/2+1,N);
	if(mae.equals(ato)){
	    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