def vector_maths(wvs, pwords=None, nwords=None, n=1):
    """ Perform word vector maths


    Parameters
    ----------
    wvs : :obj:`gensim.model`
        Trained word vector model
    pwords : :obj:`list`
        list of positive words
    nwords : :obj:`list`
        list of negative words
    n  : :obj:`int`
        Number of close words to return.

    Returns
    -------
        most_similar : :obj:`list`
            list of most similar words and their distance
    """
    most_similar = wvs.wv.most_similar(positive=pwords, negative=nwords, topn=n
        )
    return most_similar
