import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	}
} Main public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	} main {
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	} Scanner stdIn = new Scanner(System.in); stdIn new Scanner(System.in) String S = stdIn.next(); S stdIn.next() stdIn.next stdIn int N = S.length(); N S.length() S.length S String S1 = S.substring(0, N / 2); S1 S.substring(0, N / 2) S.substring S 0 N / 2 N 2 String S2 = S.substring(((N + 3) / 2) - 1 , N); S2 S.substring(((N + 3) / 2) - 1 , N) S.substring S ((N + 3) / 2) - 1 ((N + 3) / 2) (N + 3) N 3 2 1 N System.out.println(S1.equals(S2) ? "Yes" : "No") System.out.println System.out System System.out S1.equals(S2) ? "Yes" : "No" S1.equals(S2) S1.equals S1 S2 "Yes" "No" stdIn.close() stdIn.close stdIn String[] args args public class Main {
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	}
} public class Main {
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		Scanner stdIn = new Scanner(System.in);
		String S = stdIn.next();
		int N = S.length();
		String S1 = S.substring(0, N / 2);
		String S2 = S.substring(((N + 3) / 2) - 1 , N);
		System.out.println(S1.equals(S2) ? "Yes" : "No");

		stdIn.close();
	}
}