class Student {

	private String firstName = null;

	public Student(String fname) throws InvalidDataException, InvalidDataException2  {
		if (fname == null) {
			throw new InvalidDataException();
		}
		else if (fname.equals("")) {
			throw new InvalidDataException2();
		}
	
		firstName = fname;
	}

	@Override
	public String toString() {
		return firstName;
	}
}