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