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

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

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

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

        int N = S.length();
        int Aend = (N-1)/2;
        int Bstart = (N+3)/2;
	
        if(S.substring(0,(N-1)/2). equals (S.substring((N+3)/2-1,N))){
        System.out.println("Yes");
        }else{
        System.out.println("No");
        }
	}
} Main
import 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 Aend = (N-1)/2;
        int Bstart = (N+3)/2;
	
        if(S.substring(0,(N-1)/2). equals (S.substring((N+3)/2-1,N))){
        System.out.println("Yes");
        }else{
        System.out.println("No");
        }
	}
}