# functions go here


def yes_no (question):
    """check the user says yes / no / y / n (y/n), returns 'yes' or 'no' """
    while True:

        response =input(question).lower()


       # check the user says yes / no / y / n
        if response == "yes" or response == "y" :
            return "yes"
        elif response == "no" or response == "n" :
           return "no"
        else:
            print("please enter yes / no")




# Main routine

# ask the user if they want instructions (check they say yes / no)
want_instructions =yes_no("Do you want to see the instructions? ").

# Display the insrtuctions if the user wants to see them...
if want_instructions == "yes":
    instructions()

    print()
    print("Program continues")