I want this in java. how can I extend my program to 9999?

import java.util.Scanner;

public class Main

{

public static void main(String[] args)

{

Scanner in = new Scanner(System.in);

System.out.print("Please enter a positive integer

int input = in.nextInt();

System.out.println(intName(input));

}

public static String intName(int number)

{

int part = number;

String name = "";

if (part >= 100)

{

name = digitName(part / 100) + " hundred";

part = part % 100;

}

if (part >= 20)

{

name = name + " " + tensName(part);

part = part % 10;

}

else if (part >= 10)

{

name = name + " " + teenName(part);

part = 0;

}

if (part > 0)

{

name = name + " " + digitName(part);

}

return name;

}

public static String digitName(int digit)

{

String [ ] digitStrings = {"", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };

if (digit >=0 && digit

return digitStrings[digit];

else return "";

}

public static String teenName(int number)

{

switch (number)

{

case 10: return "ten";

case 11: return "eleven";

case 12: return "twelve";

case 13: return "thirteen";

case 14: return "fourteen";

case 15: return "fifteen";

case 16: return "sixteen";

case 17: return "seventeen";

case 18: return "eighteen";

case 19: return "nineteen";

default: return "";

}

}

public static String tensName(int number)

{

if (number >= 90) { return "ninety"; }

if (number >= 80) { return "eighty"; }

if (number >= 70) { return "seventy"; }

if (number >= 60) { return "sixty"; }

if (number >= 50) { return "fifty"; }

if (number >= 40) { return "forty"; }

if (number >= 30) { return "thirty"; }

if (number >= 20) { return "twenty"; }

return "";

}

public static String ninethousandName(int number)

{

if (number >= 90) { return "ninety"; }

if (number >= 80) { return "eighty"; }

if (number >= 70) { return "seventy"; }

if (number >= 60) { return "sixty"; }

if (number >= 50) { return "fifty"; }

if (number >= 40) { return "forty"; }

if (number >= 30) { return "thirty"; }

if (number >= 20) { return "twenty"; }

return "";

}

}

Assignment Content Question 1 100 Points Review the BankCheckAmount.java program and extend it to print the words for amounts up to 9999. Currently, the biggest amount is 999. Upload your .java file and the output of running your program to show that it works. Note the three different ways that each of the methods uses to select the String that it returns. Use the editor to format your answer Additional content You can add text, images, and files here