import java.util.regex.*;
public class QuizCheck
{
   /**
      Checks whether a string of quiz answers is valid. It must
      contain an answer A, B, C, or D for each expected answer, or an
      X to indicate that no answer was provided.
      @param input the answer string
      @param questions the number of questions in the string
      @return true if the string was valid, false otherwise
   */
   public static boolean checkInputs(String input, int questions)
   {
      if(input.length() != questions){return false;}
      if(input.length() != 0)
      {
        for(int i = 0; i < input.length(); i++)
        {
           switch(input.charAt(i))
           {
            case 'A':
               break;
            case 'B':
               break;
            case 'C':
               break;
            case 'D':
               break;
            case 'X':
               break;
            default:
               return false;
           }
        }
      }
      return true;
   }
}