I'm getting an error in my code..

public class Hangman {

  public static void main(String[] args) {

      Game game = new Game("treehouse" );
      Prompter prompter = new Prompter(game);

      boolean isHit = prompter.promptForGuess();

      if (isHit){
          System.out.println("We got a hit!");
      } else{
          System.out.println("It's a miss!"); 
      }
  }
}

class Game{
    //the game logic comes here  
    private String answer;
    private String hits;
    private String misses;

    public Game(String answer){
        this.answer = answer;
        hits = "";
        misses = "";
    }

    public boolean applyGuess(char letter){
        boolean isHit = answer.indexOf(letter) != -1;
        if (isHit){
            hits += letter;
        } else{
            misses += letter;
        }
        return isHit;
    }

}```
```Prompter.java
import.java.util.Scanner;

class Prompter{
    //all I/O is in here
    private Game game;

    public Prompter(Game game){
        this.game = game;
    }

    public boolean promptForGuess(){
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter a letter:  ");
        String guessInput = scanner.nextLine();
        char guess = guessInput.charAt(0);
        return game.applyGuess(guess);
    }
}```