import java.util.Scanner;

public class Main {

	private static Scanner scan = new Scanner(System.in);

	public static void main(String[] args) {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}
} import java.util.Scanner; Scanner java.util public class Main {

	private static Scanner scan = new Scanner(System.in);

	public static void main(String[] args) {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}
} Main private static Scanner scan = new Scanner(System.in); scan new Scanner(System.in) public static void main(String[] args) {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	} main {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	} String s = scan.next(); s scan.next() scan.next scan int a = (s.length() -1)/2; a (s.length() -1)/2 (s.length() -1) s.length() s.length s 1 2 int b = (s.length()+3)/2-1; b (s.length()+3)/2-1 (s.length()+3)/2 (s.length()+3) s.length() s.length s 3 2 1 String fString = s.substring(0 , a); fString s.substring(0 , a) s.substring s 0 a String lString = s.substring(b, s.length()); lString s.substring(b, s.length()) s.substring s b s.length() s.length s if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		} fString.equals(lString) fString.equals fString lString {
			System.out.println("Yes");
		} System.out.println("Yes") System.out.println System.out System System.out "Yes" {
			System.out.println("No");
		} System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {

	private static Scanner scan = new Scanner(System.in);

	public static void main(String[] args) {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}
} public class Main {

	private static Scanner scan = new Scanner(System.in);

	public static void main(String[] args) {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}
} Main
import java.util.Scanner;

public class Main {

	private static Scanner scan = new Scanner(System.in);

	public static void main(String[] args) {

		String s = scan.next();
		int a = (s.length() -1)/2;
		int b = (s.length()+3)/2-1;
		String fString = s.substring(0 , a);
		String lString = s.substring(b, s.length());

		if(fString.equals(lString)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

	}
}