import java.util.Scanner;
class Main{
 public static void main(String args[]){
   Scanner sc = new Scanner(System.in);
   String s = sc.next();
   int n = s.length();
   String x , y;
   x = s.substring(0,n/2);
   y = s.substring(n/2+1,n);
   if(x.equals(y)){
     System.out.println("Yes");
   }else{
     System.out.println("No");
   }
 
 }
} import java.util.Scanner; Scanner java.util class Main{
 public static void main(String args[]){
   Scanner sc = new Scanner(System.in);
   String s = sc.next();
   int n = s.length();
   String x , y;
   x = s.substring(0,n/2);
   y = s.substring(n/2+1,n);
   if(x.equals(y)){
     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();
   String x , y;
   x = s.substring(0,n/2);
   y = s.substring(n/2+1,n);
   if(x.equals(y)){
     System.out.println("Yes");
   }else{
     System.out.println("No");
   }
 
 } main {
   Scanner sc = new Scanner(System.in);
   String s = sc.next();
   int n = s.length();
   String x , y;
   x = s.substring(0,n/2);
   y = s.substring(n/2+1,n);
   if(x.equals(y)){
     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 String x x y; y x = s.substring(0,n/2) x s.substring(0,n/2) s.substring s 0 n/2 n 2 y = s.substring(n/2+1,n) y s.substring(n/2+1,n) s.substring s n/2+1 n/2 n 2 1 n if(x.equals(y)){
     System.out.println("Yes");
   }else{
     System.out.println("No");
   } x.equals(y) x.equals x y {
     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
import java.util.Scanner;
class Main{
 public static void main(String args[]){
   Scanner sc = new Scanner(System.in);
   String s = sc.next();
   int n = s.length();
   String x , y;
   x = s.substring(0,n/2);
   y = s.substring(n/2+1,n);
   if(x.equals(y)){
     System.out.println("Yes");
   }else{
     System.out.println("No");
   }
 
 }
}