def stock_availability(inventory, to_do, *args):
    cupcakes = [el for el in inventory]

    if to_do == "delivery":
        for el in args:
            cupcakes.append(el)

    elif to_do == "sell":
        if args:
            if type(*args) == int:
                  cupcakes = []

            else:
                for el in cupcakes:
                    if el == args:
                        cupcakes.remove(el)
        else:
            cupcakes = cupcakes[1::]

    return cupcakes