def construct_vocab(words1, words2):
    """Combines words from two sentences into a single
        dictionary
        Input: words1 - List of strings
               words2 - List of strings
        Output: vocab - dictionary where key is word,
                            value is weight of word"""
    all_words = set(words1 + words2)
    vocab = {}
    for word in all_words:
        # Give words in this list higher weighting as it almost certainly means a promotion
        if word in ['virtual-assist']:
            vocab[word] = 2
        else:
            vocab[word] = 1
    return vocab