
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String S = scan.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	}
} 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.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	}
} Main public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String S = scan.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	} main {

		Scanner scan = new Scanner(System.in);
		String S = scan.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String S = scan.nextLine(); S scan.nextLine() scan.nextLine scan int N = S.length(); N S.length() S.length S if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		} S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N)) S.substring(0, (N - 1) / 2).equals S.substring(0, (N - 1) / 2) S.substring S 0 (N - 1) / 2 (N - 1) N 1 2 S.substring((N + 1) / 2, N) S.substring S (N + 1) / 2 (N + 1) N 1 2 N {
			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" scan.close() scan.close scan String[] args args public class Main {
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String S = scan.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	}
} public class Main {
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String S = scan.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	}
} Main

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);
		String S = scan.nextLine();
		int N = S.length();

		if (S.substring(0, (N - 1) / 2).equals(S.substring((N + 1) / 2, N))) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}

		scan.close();
	}
}
