# DO NOT CHANGE THE IMPORTS!

def calculate_price(articles: dict[str, int], cart: dict[str, int]) -> float:
    price = 0
    for name, amount in cart.items():
        if name in articles:
            price += articles[name] * amount
    return price / 100


def by_amount(articles: dict[str, int], cart: dict[str, int]) -> dict[int, list[str]]:
    out: dict[int, list[str]] = dict()
    for name, amount in cart.items():
        if name not in articles:
            continue
        if amount not in out:
            out[amount] = [name]
        else:
            out[amount] += [name]
    return out


if __name__ == "__main__":
    articles_dict = {"apples": 100, "oranges": 100,
                     "lemons": 200, "avocado": 500}
    cart_dict = {"apples": 2, "oranges": 2, "lemons": 1, "bananas": 5}

    assert calculate_price(articles_dict, cart_dict) == 6.0

    assert by_amount(articles_dict, cart_dict) == {
        2: ['apples', 'oranges'], 1: ['lemons']}