import java.util.*;
class WordBank {
    private Set<String> wordBank = new HashSet<>();
    private Random r = new Random();
    static WordBank obj = new WordBank();

    public int setSize() {
        return (wordBank.size());

    }

    private WordBank() {
    }

    public static WordBank getObject() {
        return obj;
    }

    public void addWord(String word) {

        for (String i : wordBank) {
            if (word.equals(i)) {
                System.out.println("This word already exists! ");
                return;

            }
        }
        if (word == null || word.equals("")) {
            System.out.println("Word is not valid!");
            return;
        }
        wordBank.add(word);

    }

    public String getRandomWord() {
        if (wordBank.size() == 0) {
            System.out.println("there is no word in Word Bank \n");
            return ("there is no word in Word Bank ");
        }
        Object[] wordBankArray = wordBank.toArray();
        int a = r.nextInt(wordBankArray.length);

        return ((String) wordBankArray[a]);

    }
}