def distinct_words(corpus):
    """ Determine a list of distinct words for the corpus.
        Params:
            corpus (list of list of strings): corpus of documents
        Return:
            corpus_words (list of strings): list of distinct words across the corpus, sorted (using python 'sorted' function)
            num_corpus_words (integer): number of distinct words across the corpus
    """
    corpus_words = []
    num_corpus_words = -1
    
    # ------------------
    # Write your implementation here.
    corpus_words = [y for x in corpus for y in x]
    corpus_words = sorted(list(set(corpus_words)))
    num_corpus_words = len(corpus_words)    


    # ------------------

    return corpus_words, num_corpus_words