def christmas_gifts(gifts, maximum_price):
    """
    IMPORTANT: You should NOT use loops or list comprehensions for this question.
    Instead, use lambda functions, map, and/or filter.

    Given a list of tuples (Gift, Price), return the list of presents you bought.
    You should buy any present the price of which is below or equal to the maximum price.

    >>> gifts = [('Laptop', 100), ('PS5', 150), ('car', 500), \
    ('Plane ticket', 150)]
    >>> christmas_gifts(gifts, 200)
    ['Laptop', 'PS5', 'Plane ticket']

    >>> gifts = [('Phone', 10), ('PS5', 150), ('car', 500), \
    ('Laptop', 50), ('Clothes', 21)]
    >>> christmas_gifts(gifts, 10)
    ['Phone']
    """
    return list(map(lambda gift_name: gift_name[0],list(filter(lambda gift: True if gift[1] <= maximum_price else False, gifts))))