import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
} Main public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	} main {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String S = scan.next() ; S scan.next() scan.next scan int N = S.length(); N S.length() S.length S String left = S.substring(0, (N-1)/2); left S.substring(0, (N-1)/2) S.substring S 0 (N-1)/2 (N-1) N 1 2 String right = S.substring((N+3)/2-1, N); right S.substring((N+3)/2-1, N) S.substring S (N+3)/2-1 (N+3)/2 (N+3) N 3 2 1 N if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		} left.equals(right) left.equals left right {
			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 {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
} public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		String S = scan.next() ;

		// Sの長さ
		int N = S.length();

		String left = S.substring(0, (N-1)/2);
		String right = S.substring((N+3)/2-1, N);


		if(left.equals(right)){
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
}
