# Checks that users enter an integer
# that is more than 13
def int_checker():

    while True:
        error = "Please enter an integer more than / equal to 13."

        try:
            response = int(input("What is the game goal? "))

            # checks that the number is more than / equal to 13
            if response < 13:
                print(error)
            else:
                return response

        except ValueError:
            print(error)


# main routine starts here
game_goal = int_checker()
print(game_goal)