/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
public static void main(String[] args){
      String word = "stack";
 
      String methodddd = method4(word);
      System.out.println(methodddd);
   }
 
public static String method4(String word){
    int length = word.length();
    if (length == 0){
         return "";
    }
    String last = word.substring(length-1, length);
    return  last + last + last +  method4(word.substring(0, length-1));
}
 
}

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