Exception in thread "main" java.lang.OutOfMemoryError: Java heap space

package com.teamtreehouse;

public class Main {

    public static void main(String[] args)  {
        // write your code here
        Prompter prompter = new Prompter();
        // Collects a template for the story and creates a template correctly formatted.
        Template tmpl = new Template(prompter.promptForStory());
        // Collects words for every empty space in story
        prompter.run(tmpl);
    }
}

package com.teamtreehouse;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;


public class Prompter {
    private BufferedReader mReader;
    private Set<String> mCensoredWords;

    public Prompter() {
        mReader = new BufferedReader(new InputStreamReader(System.in));
        loadCensoredWords();
    }

    private void loadCensoredWords() {
        mCensoredWords = new HashSet<String>();
        Path file = Paths.get("resources", "censored_words.txt");
        List<String> words = null;
        try {
            words = Files.readAllLines(file);
        } catch (IOException e) {
            System.out.println("Couldn't load censored words");
            e.printStackTrace();
        }
        mCensoredWords.addAll(words);
    }

    public void run(Template tmpl) {
        List<String> enteredWords = null;
        try {
            enteredWords = promptForWords(tmpl);
        } catch (IOException e) {
            System.out.println("There was a problem prompting for words");
            e.printStackTrace();
            System.exit(0);
        }
        String results = tmpl.render(enteredWords);
        System.out.printf("Your TreeStory:%n%n%s", results);
    }

    public String promptForStory() {
        System.out.print("Enter a story with words to be changed in format \"__noun__\":  ");
        BufferedReader mReader = new BufferedReader(new InputStreamReader(System.in));
        String story = "";
        try {
            story = mReader.readLine();
        } catch (IOException e) {
            System.out.println("There was an error while entering your story template.");
            e.printStackTrace();
            System.exit(0);
        }
        return story;
    }

    /**
     * Prompts user for each of the blanks
     *
     * @param tmpl The compiled template
     * @return
     * @throws IOException
     */
    public List<String> promptForWords(Template tmpl) throws IOException {
        List<String> words = new ArrayList<>();
        for (String phrase : tmpl.getPlaceHolders()) {
            String word = promptForWord(phrase);
            words.add(word);
        }
        return words;
    }


    /**
     * Prompts the user for the answer to the fill in the blank.  Value is guaranteed to be not in the censored words list.
     *
     * @param phrase The word that the user should be prompted.  eg: adjective, proper noun, name
     * @return What the user responded
     */
    public String promptForWord(String phrase) throws IOException {
        String word;
        boolean isRestricted;

        do {
            System.out.printf("Enter %s:  ", phrase);
            word = mReader.readLine();
            if (word == null
                    || mCensoredWords.contains(word.replaceAll("\\s", "").toLowerCase())
                    || word.length() == 0) {
                isRestricted = true;
                System.out.println("You entered an invalid word. Try again.");
            } else {
                isRestricted = false;
            }
        } while (isRestricted);

        return word;
    }
}