import java.util.*;
import java.lang.*;

public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    }
} import java.util.*; util.* java import java.lang.*; lang.* java public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    }
} Main public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    } main {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) String x = scanner.next(); x scanner.next() scanner.next scanner String[] xx = x.split(""); xx x.split("") x.split x "" String check_char_one = new String(); check_char_one new String() String check_char_two = new String(); check_char_two new String() for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        } int i = 0; int i = 0; i 0 i < xx.length / 2 i xx.length / 2 xx.length xx xx.length 2 i++ i++ i {
            check_char_one += xx[i];
        } {
            check_char_one += xx[i];
        } check_char_one += xx[i] check_char_one xx[i] xx i for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        } int i = ((xx.length + 3 ) / 2 -1); int i = ((xx.length + 3 ) / 2 -1); i ((xx.length + 3 ) / 2 -1) (xx.length + 3 ) / 2 (xx.length + 3 ) xx.length xx xx.length 3 2 1 i < xx.length i xx.length xx xx.length i++ i++ i {
            check_char_two += xx[i];
        } {
            check_char_two += xx[i];
        } check_char_two += xx[i] check_char_two xx[i] xx i if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        } check_char_one.equals(check_char_two) check_char_one.equals check_char_one check_char_two {
            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) {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    }
} public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    }
} Main
import java.util.*;
import java.lang.*;

public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        String x = scanner.next();
        String[] xx = x.split("");


        String check_char_one = new String();
        String check_char_two = new String();

        for (int i = 0; i < xx.length / 2; i++) {
            check_char_one += xx[i];
        }

        for (int i = ((xx.length + 3 ) / 2 -1); i < xx.length; i++) {
            check_char_two += xx[i];
        }

        if (check_char_one.equals(check_char_two)) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }

    }
}