# ------------------------ Functions ------------------------ #

def int_check(question, low=None, high=None, exit_code=None):
    """Check that input is an integer within bounds; return 'exit_code' if entered."""

    if low is None and high is None:
        error = "Please enter an integer."
    elif low is not None and high is None:
        error = f"Please enter an integer that is more than or equal to {low}."
    else:
        error = f"Please enter an integer between {low} and {high} (inclusive)."

    while True:
        response = input(question).lower()

        if response == exit_code:
            return response
        try:
            response = int(response)
            if low is not None and response < low:
                print(error)
            elif high is not None and response > high:
                print(error)
            else:
                return response
        except ValueError:
            print(error)

# ------------------------ Main Routine (Sample Test Area) ------------------------ #

# Example use case: simulate a user guessing answers to basic math questions
guess = ""
while guess != "xxx":
    guess = int_check("Enter your answer (0-10) or 'xxx' to quit: ", low=0, high=10, exit_code="xxx")
    if guess != "xxx":
        print(f"You answered: {guess}\n")
    else:
        print("Exiting the quiz.\n")