def extract_unique_words(list_of_tup):
    """
    :param list_of_tup: list of tuples
    :return: The unique words from all the reviews
    """
    unique_wrs = set()
    for review in list_of_tup:
        for pair in review:
            unique_wrs.add(pair[0])
    return sorted(list(unique_wrs))