Display Number in Words ISC Computer Science 2011 Practical

Write a program to input a natural number less than 1000 and display it in words. Test your program for the given sample data and some random data.
INPUT: 29
OUTPUT: TWENTY NINE
INPUT: 17001
OUTPUT: OUT OF RANGE
INPUT: 119
OUTPUT: ONE HUNDRED AND NINETEEN
INPUT: 500
OUTPUT: FIVE HUNDRED

import java.util.Scanner;
class Words{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        System.out.println("Enter natural number < 1000");
        int num = Integer.parseInt(in.nextLine());
        if(num >= 1000){
            System.out.println("OUT OF RANGE");
            return;
        }
        int hundreds = num / 100;
        int tens = (num % 100);
        int ones = (num % 100) % 10;
        String w[] = {"ZERO", "ONE", "TWO", "THREE", "FOUR", "FIVE", "SIX", "SEVEN", "EIGHT", "NINE", "TEN", "ELEVEN", "TWELVE", "THIRTEEN", "FOURTEEN", "FIFTEEN", "SIXTEEN", "SEVENTEEN", "EIGHTEEN", "NINETEEN"};
        String tn[] = {"ZERO", "TEN", "TWENTY", "THIRTY", "FORTY", "FIFTY", "SIXTY", "SEVENTY", "EIGHTY", "NINETY"};
        if(hundreds > 0)
            System.out.print(w[hundreds] + " HUNDRED ");
        if(tens > 0 && tens < 20)
            System.out.print(w[tens] + " ");
        else if(tens > 1)
            System.out.print(tn[tens / 10] + " ");
        if(ones > 0 && tens > 19)
            System.out.println(w[ones]);
    }
}