# Check that users have entered a valid answer
# option based on list
def string_checker(question, valid_ans):

    error = "Please enter a valid option from the following list: ", yes_no

    while True:

        # Get user response and make sure it's lowercase
        user_response = input(question).lower()

        for item in valid_ans:
            # check if the user response is a word in the list
            if item == user_response:
                return item

            # check if the user response is the same as
            # the first letter of an item in the list
            elif user_response == item[0]:
                return item

        # print error if user does not entre something that is valid
        print(error)
        print()

# Displays instructions
def instructions():
    """Print instructions"""

    print("""
*** Instructions ****

To begin, choose the number of rounds (you can play between 5 and 20 rounds)

Then answer the multiplication question. Give it your best go! 
Your game statistics will be published at the end of the game. 

Good Luck!
    """)

# Main Routine Starts here

# Game heading
print("\n🔢✏️✖️ Welcome to the multiplication quiz! ✖️✏️🔢")
print()

yes_no = ["yes", "no"]

# ask user if they want to see the instructions and display
# them if requested
want_instructions = string_checker("Do you want to see the instructions? ", yes_no)

# checks users enters yes (y) or no (n)
if want_instructions == "yes":
    instructions()

print()
print("Program continues")