import java.util.*;

public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    }

    static boolean isKaibun(String str) {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    }
} import java.util.*; util.* java public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    }

    static boolean isKaibun(String str) {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    }
} Main static Scanner sc = new Scanner(System.in); sc new Scanner(System.in) public static void main(String[] args) {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    } main {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    } String s = sc.next(); s sc.next() sc.next sc String s0 = s.substring(0, (s.length() - 1) / 2); s0 s.substring(0, (s.length() - 1) / 2) s.substring s 0 (s.length() - 1) / 2 (s.length() - 1) s.length() s.length s 1 2 String s1 = s.substring((s.length() + 1) / 2); s1 s.substring((s.length() + 1) / 2) s.substring s (s.length() + 1) / 2 (s.length() + 1) s.length() s.length s 1 2 System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No") System.out.println System.out System System.out isKaibun(s0) && s0.equals(s1) ? "Yes" : "No" isKaibun(s0) && s0.equals(s1) isKaibun(s0) isKaibun s0 s0.equals(s1) s0.equals s0 s1 "Yes" "No" String[] args args static boolean isKaibun(String str) {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    } isKaibun {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    } return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false; str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false str.length() <= 1 str.length() str.length str 1 true str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false str.charAt(0) == str.charAt(str.length() -1) str.charAt(0) str.charAt str 0 str.charAt(str.length() -1) str.charAt str str.length() -1 str.length() str.length str 1 isKaibun(str.substring(1, str.length() - 1)) isKaibun str.substring(1, str.length() - 1) str.substring str 1 str.length() - 1 str.length() str.length str 1 false String str str public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    }

    static boolean isKaibun(String str) {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    }
} public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    }

    static boolean isKaibun(String str) {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    }
} Main
import java.util.*;

public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String s = sc.next();
        String s0 = s.substring(0, (s.length() - 1) / 2);
        String s1 = s.substring((s.length() + 1) / 2);
        System.out.println(isKaibun(s0) && s0.equals(s1) ? "Yes" : "No");
    }

    static boolean isKaibun(String str) {
        return str.length() <= 1 ? true :
                str.charAt(0) == str.charAt(str.length() -1) ? isKaibun(str.substring(1, str.length() - 1)) : false;
    }
}
