import java.util.Scanner;

public class Main {
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

		sc.close();
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

		sc.close();
	}
} Main public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

		sc.close();
	} main {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc int N = S.length(); N S.length() S.length S int hantei1=((N-1)/2); hantei1 ((N-1)/2) (N-1) N 1 2 int hantei2=((N+3)/2)-1; hantei2 ((N+3)/2)-1 ((N+3)/2) (N+3) N 3 2 1 String a1 = S.substring(0, hantei1); a1 S.substring(0, hantei1) S.substring S 0 hantei1 String a2 = S.substring(hantei2, N); a2 S.substring(hantei2, N) S.substring S hantei2 N if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		} a1.equals(a2) a1.equals a1 a2 {
			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" sc.close() sc.close sc String args[] args public class Main {
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

		sc.close();
	}
} public class Main {
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

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

public class Main {
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		int N = S.length();
		int hantei1=((N-1)/2);
		int hantei2=((N+3)/2)-1;
		String a1 = S.substring(0, hantei1);
		String a2 = S.substring(hantei2, N);
		
		if(a1.equals(a2)) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}

		sc.close();
	}
}