import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    }
} Main public static void main(String[] args) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    } main {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) String S = scanner.next(); S scanner.next() scanner.next scanner int L = S.length(); L S.length() S.length S String[] str = S.split(""); str S.split("") S.split S "" String str1 = ""; str1 "" String str2 = ""; str2 "" for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        } int i=0; int i=0; i 0 i<(L-1)/2 i (L-1)/2 (L-1) L 1 2 i++ i++ i {
            str1 += str[i];
        } {
            str1 += str[i];
        } str1 += str[i] str1 str[i] str i for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        } int i=((L+3)/2)-1; int i=((L+3)/2)-1; i ((L+3)/2)-1 ((L+3)/2) (L+3) L 3 2 1 i<L i L i++ i++ i {
            str2 += str[i];
        } {
            str2 += str[i];
        } str2 += str[i] str2 str[i] str i if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        } str1.equals(str2) str1.equals str1 str2 {
            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) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        String S = scanner.next();
        int L = S.length(); 
        String[] str = S.split("");
        String str1 = "";
        String str2 = "";
        
        for(int i=0; i<(L-1)/2; i++){
            str1 += str[i];
        }
        
        for(int i=((L+3)/2)-1; i<L; i++){
            str2 += str[i];
        }  
        
        if(str1.equals(str2)){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
        
    }
}
