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();
    String case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      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();
    String case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      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 case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      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 case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      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 case1 = S.substring(0, N/2); case1 S.substring(0, N/2) S.substring S 0 N/2 N 2 String case2 = S.substring((N+3)/2-1, N); case2 S.substring((N+3)/2-1, N) S.substring S (N+3)/2-1 (N+3)/2 (N+3) N 3 2 1 N if(case1.equals(case2)){
      System.out.println("Yes");
    }else{
      System.out.println("No");
    } case1.equals(case2) case1.equals case1 case2 {
      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();
    String case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      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();
    String case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      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();
    String case1 = S.substring(0, N/2);
    String case2 = S.substring((N+3)/2-1, N);
    if(case1.equals(case2)){
      System.out.println("Yes");
    }else{
      System.out.println("No");
    }
  }
}
  