import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String kaibun = sc.next();
		int mojisuu = kaibun.length();

		if(kaibun.substring(0,(mojisuu-1)/2).equals(kaibun.substring((mojisuu+3)/2-1,mojisuu))) {
			System.out.print("Yes");
		}
		else {
			System.out.print("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