recursiveSum.java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {

    /*
     * Complete the 'superDigit' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts following parameters:
     *  1. STRING n
     *  2. INTEGER k
     */

    public static int superDigit(String n, int k) {
    // Write your code here
      int digit;
      int sum = 0;
    for(int i=0;i<k;i++){
      n+=n;
    }
    int number=Integer.parseInt("200");  
    while(number > 0)  
      {  
            //finds the last digit of the given number    
            digit = number % 10;  
            //adds last digit to the variable sum  
            sum = sum + digit;  
            //removes the last digit from the number  
            number = number / 10;  
      }  
      return sum;
    }

}

class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        String[] firstMultipleInput = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");

        String n = firstMultipleInput[0];

        int k = Integer.parseInt(firstMultipleInput[1]);

        int result = Result.superDigit(n, k);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}