def user_confirm(prompt):
    """
    Recursively prompts until user says sg starting with "Y/y" or "N/n"
    """
    valid = ['Y', 'N']
    answer = input(prompt)

    # Ask again if user hits enter without answer
    chars = len(answer)
    if chars == 0:
        return user_confirm(prompt)

    # Take first letter of answer and make it uppercase
    answer = answer[0].upper()

    if answer not in valid:
        print('Answer yes or no.')
        return user_confirm(prompt)

    return answer